Uniquely identifying target femtocell to facilitate femto-assisted active hand-in

ABSTRACT

Systems, methods, and devices are described for supporting macrocell-to-femtocell hand-ins of active macro communications for mobile devices. An out-of-band (OOB) link is used to detect that a mobile device is in proximity of a femtocell. Having detected the mobile device in proximity to the femtocell, an OOB proximity detection is communicated to a femtocell gateway disposed in a core network in communication with the macro network to effectively pre-register the mobile device with the femto-convergence system. When the femtocell gateway receives a handover request from the macro network implicating the pre-registered mobile device, it is able to reliably determine the appropriate target femtocell to use for the hand-in according to the pre-registration, even where identification of the appropriate target femtocell would otherwise be unreliable. Some embodiments may also handling registering the mobile device after a handover request has occurred, including tiered approaches.

CROSS REFERENCES

The present Application claims priority to Provisional Application No.61/393,533 entitled “Uniquely Identifying Target Femtocell to FacilitateFemto-Assisted Active Hand-in” filed Oct. 15, 2010, and assigned to theassignee hereof and hereby expressly incorporated by reference herein.This application is also related to: U.S. patent application Ser. No.______, entitled “PROXIMITY DETECTION FOR FEMTOCELLS USING OUT-OF-BANDLINKS,” and referenced as Qualcomm Docket No. 102971, and U.S. patentapplication Ser. No. ______, entitled “FEMTOCELL INDICATION OF MOBILEDEVICE PROXIMITY AND TRANSMISSION OF MOBILE IDENTITY TO ASSIST INRESOLVING FEMTOCELL DISAMBIGUATION,” and referenced as Qualcomm DocketNo. 110936, each assigned to the assignee hereof and hereby expresslyincorporated by reference herein.

BACKGROUND

Communication networks are in wide use today, and often have multipledevices in communication over wireless links to carry voice and data.Many of these devices, such as cellular phones, smartphones, laptops,and tablets, are mobile, and may connect with a network wirelessly via abase station, access point, wireless router, or Node B (collectivelyreferred to herein as “access points”). A mobile device may remainwithin the service area of such an access point for a relatively longperiod of time (thereby being “camped on” the access point) or maytravel relatively rapidly through access point service areas, withcellular handover or reselection techniques being used for maintaining acommunication session, or for idle mode operation as association withaccess points is changed.

Issues with respect to available spectrum, bandwidth, or capacity mayresult in an access being unavailable or inadequate between certainmobile devices and an access point. Likewise, issues with respect towireless signal propagation (e.g., shadowing, multipath fading,interference, etc.) may result in access being unavailable forparticular mobile devices.

Cellular networks have employed the use of various cell types, such asmacrocells, microcells, picocells, and femtocells, to provide desiredbandwidth, capacity, and wireless communication coverage within serviceareas. Femtocells may be used to provide wireless communication in areasof poor network coverage (e.g., inside of buildings), to provideincreased network capacity, and to utilize broadband network capacityfor backhaul. There may be a need in the art for novel functionality toaccurately identify femtocells for a macrocell to femtocell hand-in.

SUMMARY

The present disclosure is directed to systems and methods for supportingmacrocell-to-femtocell hand-ins of active macro communications formobile devices. A femtocell detects a mobile device in its proximity(e.g., using an out-of-band link established by an out-of-band radiointegrated with the femtocell as part of a femto-proxy system). Havingdetected the mobile device in its proximity, the femtocell communicatesan OOB presence indicator to pre-register the mobile device with afemtocell gateway (e.g., another type of interface gateway) disposed ina core network in communication with the macro network. When thefemtocell gateway receives a handover request from the macro networkimplicating the pre-registered mobile device, the femtocell gateway isable to reliably determine the appropriate femtocell to use for thehand-in according to the OOB presence indication. The OOB presenceindication can be carried in an existing message between femtocell andfemtocell gateway such as a registration message, handover responsemessage, or an OOB presence message can be defined to communicate thisindication.

Some embodiments include a method for macrocell-to-femtocell hand-in. Auser equipment may be in proximity to a femtocell using an out-of-band(OOB) communications link. A user equipment identifier may be identifiedcorresponding to the user equipment detected in proximity to thefemtocell using the OOB communications link. The user equipment may beregistered for hand-in from a macrocell to the femtocell bycommunicating, from the femtocell to a femtocell gateway, the userequipment identifier and indicating OOB proximity detection of the userequipment at the femtocell.

Identifying the user equipment identifier may include receiving an OOBidentifier associated with the user equipment identifier over the OOBcommunications link. Identifying the user equipment identifier mayinclude receiving a macro identifier associated with the user equipmentidentifier over the OOB communications link. Registering the userequipment for hand-in from the macrocell to the femtocell may includetransmitting a registration message from the femtocell to the femtocellgateway. Registering the user equipment for hand-in from the macrocellto the femtocell may include transmitting an OOB indication message fromthe femtocell to the femtocell gateway.

In some embodiments, the method for macrocell-to-femtocell hand-in mayfurther include utilizing a user equipment mapping between a macroidentifier of the user equipment with the OOB identifier to determinethe user equipment identifier. Detecting the user equipment in proximityto the femtocell may include paging the user equipment over the OOBcommunications link; and detecting a response to the paging from theuser equipment over the OOB communications link. The response mayinclude the OOB identifier of the user equipment. In some embodiments,the response may include the macro identifier for the user equipment.

In some embodiments, the method for macrocell-to-femtocell hand-in mayfurther include receiving a handover request for the user equipment atthe femtocell from the femtocell gateway, the handover request beingconfigured to direct the user equipment to hand off activecommunications with the macro network from the macrocell to thefemtocell. The handover request may be received subsequent toregistering the user equipment for hand-in from the macrocell to thefemtocell. The handover request may be received prior to registering theuser equipment for hand-in from the macrocell to the femtocell; anddetecting the user equipment may include detecting the user equipment inresponse to receiving the handover request. Detecting the user equipmentin response to receiving the handover request may include detecting theuser equipment over the OOB communications link utilizing an OOBidentifier of the user equipment. In some embodiments, detecting theuser equipment in response to receiving the handover request may includedetecting the user equipment over the OOB communications link utilizinga macro identifier of the user equipment. Registering the user equipmentmay further include transmitting a handover response accepting thehandover request.

In some embodiments, the method for macrocell-to-femtocell hand-in mayfurther include detecting a loss of the OOB communications link betweenthe user equipment and the femtocell. The user equipment may bede-registered according to detecting the loss of the OOB communicationslink.

In some embodiments, the femtocell is one of multiple femtocells on amacro network, each femtocell having a first femtocell identifieraccording to which the femtocell is non-uniquely addressable by themacro network and a second femtocell identifier according to which thefemtocell is uniquely addressable by the femtocell gateway. In someembodiments, the OOB communications link includes a Bluetooth link. Thefirst femtocell identifier of each respective femtocell may include aprimary scrambling code (PSC) of the respective femtocell. The userequipment identifier may include a macro identifier associated with theuser equipment. The macro identifier may include a International MobileSubscriber Identity (IMSI) associated with the user equipment.

Some embodiments include a femtocell that may include an in-bandfrequency module, communicatively coupled with a macro network via afemtocell gateway and configured to provide cellular network access touser equipments. The femtocell may include an out-of-band (OOB)frequency module, communicatively coupled with the in-band frequencymodule and configured to communicate with the user equipments over anOOB communications link. The femtocell may include a communicationsmanagement subsystem, communicatively coupled with the in-band frequencymodule and the OOB frequency module, and configured to: detect a userequipment in proximity to the femtocell using an out-of-band (OOB)communications link; identify a user equipment identifier correspondingto the user equipment detected in proximity to the femtocell using theOOB communications link; and register/or the user equipment for hand-infrom a macrocell to the femtocell by communicating, from the femtocellto a femtocell gateway, the user equipment identifier and indicating OOBproximity detection of the user equipment at the femtocell.

The communications management subsystem may be configured to identifythe user equipment identifier using a configuration to receive a macroidentifier associated with the user equipment identifier over the OOBcommunications link. The communications management subsystem may beconfigured to identify the user equipment identifier using aconfiguration to receive an OOB identifier associated with the userequipment identifier over the OOB communications link. Thecommunications management subsystem may be configured to register theuser equipment using a configuration to transmit a registration messagefrom the femtocell to the femtocell gateway. The communicationsmanagement subsystem may be configured to register the user equipmentusing a configuration to transmit an OOB indication message from thefemtocell to the femtocell gateway.

The communications management subsystem may be further configured toutilize a user equipment mapping between a macro identifier of the userequipment with a OOB identifier to determine the user equipmentidentifier. The communications management subsystem configured to detectthe user equipment in proximity to the femtocell may be configured to:page the user equipment over the OOB communications link; and/or detecta response to the paging from the user equipment over the OOBcommunications link. The response may include a macro identifier and/oran OOB identifier of the user equipment.

The communications management subsystem may be further configured to:receive a handover request for the user equipment at the femtocell fromthe femtocell gateway, the handover request being configured to directthe user equipment to hand off active communications with the macronetwork from the macrocell to the femtocell. The handover request may bereceived subsequent to registering the user equipment for hand-in fromthe macrocell to the femtocell. The handover request may be receivedprior to registering the user equipment for hand-in from the macrocellto the femtocell. The communications management subsystem may beconfigured to detect the user equipment by detecting the user equipmentin response to receiving the handover request. The communicationsmanagement subsystem may be configured to detect the user equipment inresponse to receiving the handover request using a configuration todetect the user equipment over the OOB communications link utilizing anOOB identifier of the user equipment. In some embodiments, a macroidentifier of the user equipment may be utilized.

In some embodiments, the communications management subsystem may befurther configured to detect a loss of the OOB communications linkbetween the user equipment and the femtocell. The user equipment may bede-registered according to detecting the loss of the OOB communicationslink. In some embodiments, the communications management subsystem maybe further configured to transmit a handover response accepting thehandover request as part of registering the user equipment. In someembodiments, the femtocell is one of multiple femtocells on a cellularnetwork, each femtocell having a first femtocell identifier according towhich the femtocell is non-uniquely addressable by the macro network anda second femtocell identifier according to which the femtocell isuniquely addressable by the femto gateway.

Some embodiments include a processor for macrocell-to-femtocell hand-in.The processor may include a communications management controller thatmay be configured to: detect a user equipment in proximity to thefemtocell using an out-of-band (OOB) communications link; identify auser equipment identifier corresponding to the user equipment detectedin proximity to the femtocell using the OOB communications link; and/orregister the user equipment for hand-in from a macrocell to thefemtocell by communicating, from the femtocell to a femtocell gateway,the user equipment identifier and indicating OOB proximity detection ofthe user equipment at the femtocell.

Some embodiments include computer program product formacrocell-to-femtocell hand-in residing on a processor-readable mediumand including processor-readable instructions, which, when executed,cause a processor to perform steps that may include: detecting a userequipment in proximity to a femtocell using an out-of-band (OOB)communications link; identifying a user equipment identifiercorresponding to the user equipment detected in proximity to thefemtocell using the OOB communications link; and/or registering the userequipment for hand-in from a macrocell to the femtocell bycommunicating, from the femtocell to a femtocell gateway, the userequipment identifier and indicating OOB proximity detection of the userequipment at the femtocell.

Some embodiments include a system for macrocell-to-femtocell hand-in.The system may include: means for detecting a user equipment inproximity to the femtocell using an out-of-band (OOB) communicationslink; means for identifying a user equipment identifier corresponding tothe user equipment detected in proximity to the femtocell using the OOBcommunications link; and/or means for registering the user equipment forhand-in from a macrocell to the femtocell by communicating, from thefemtocell to a femtocell gateway, the user equipment identifier andindicating 00B proximity detection of the user equipment at thefemtocell.

Some embodiments include a method for macrocell-to-femtocell hand-in.The method may include receiving, at a femtocell gateway from a macronetwork, a handover request configured to direct a user equipment tohand off active communications with the macro network from a macrocellto a designated femtocell with a first femtocell identifier. It may bedetermined, at the femtocell gateway, whether any of multiple femtocellsregistered the user equipment with the femtocell gateway prior toreceiving the handover request. The handover request may becommunicated, from the femtocell gateway, to the designated femtocell.

Determining, at the femtocell gateway, whether any of the multiplefemtocells registered the user equipment with the femtocell gatewayprior to receiving the handover request may include determining aregistering femtocell from the plurality of femtocells that hasregistered the user equipment prior to receiving the handover request;and/or determining that the registering femtocell is the designatedfemtocell with the first femtocell identifier. The method formacrocell-to-femtocell hand-in may further include receiving anacknowledgement message from the registering femtocell.

Determining, at the femtocell gateway, whether any of the multiplefemtocells registered the user equipment with the femtocell gatewayprior to receiving the relocation request may include determining thatnone of the multiple femtocells registered the user equipment prior toreceiving the handover request. The method may further includedetermining a set of candidate femtocells from the multiple femtocellsregistered at the femto gateway. The set of candidate femtocells may beidentified by at least the first femtocell identifier. Each of the setof candidate femtocells may be directed to detect whether the userequipment is in its proximity. An indication may be received from asuccessful femtocell of the candidate femtocells that the user equipmentis in its proximity. It may be determined that the successful femtocellis the designated femtocell. In some embodiments, the method may furtherinclude monitoring an elapsed time subsequent to directing the set ofcandidate femtocells to detect whether the user equipment is in itsproximity; and determining whether the indication from one of thecandidate femtocells that the user equipment is in its proximity isreceived while the elapsed time is within a predefined time limit.

Determining, at the femtocell gateway, whether any of the multiplefemtocells registered the user equipment prior to receiving the handoverrequest may include determining whether an OOB proximity detection isreceived from any of the plurality of femtocells prior to receiving thehandover request. The OOB proximity indication may include a macroidentifier of the user equipment.

Determining, at the femtocell gateway, whether any of the multiplefemtocells registered the user equipment prior to receiving the handoverrequest may include determining whether an OOB proximity indication isreceived from any of the multiple femtocells prior to receiving thehandover request. The OOB proximity indication may include an OOBidentifier of the user equipment. A macro identifier of the userequipment corresponding to the OOB identifier of the user equipment maybe determined.

The method of macrocell-to-femtocell hand-in may further includedetermining whether the designated femtocell is uniquely addressable bythe femtocell gateway according to the first femtocell identifier.Communicating, from the femtocell gateway, the handover request todesignated femtocell may utilize the first femtocell identifier.

Determining, at the femtocell gateway, whether any of the multiplefemtocells registered the user equipment prior to receiving the handoverrequest may include determining whether two or more femtocells of themultiple femtocells are addressable by the femtocell gateway accordingto the first femtocell identifier. Determining whether the designatedfemtocell is one of the two or more femtocells addressable according tothe first femtocell identifier may utilize a second femtocellidentifier.

In some embodiments, the method of macrocell-to-femtocell hand-in mayfurther include determining a set of candidate femtocells from themultiple femtocells; and directing, using an OOB hand-in cause value inthe handover request, each of the set of candidate femtocells to detectwhether the user equipment is in its proximity. The method may furtherinclude receiving an OOB accept message from one of the candidatefemtocells. The OOB accept message may indicate that the one of thecandidate femtocells detects the user equipment in its proximity. Themethod may include identifying one of the candidate cells associatedwith the OOB accept message as the designated femtocell. In someembodiments, the method may further receiving at least an OOB rejectmessage from one or more of the candidate femtocells or an errorindication message from one or more of the candidate femtocells and noOOB accept messages; and/or transmitting to each of the candidatefemtocells a handover request with a normal cause value. The method mayfurther include receiving at least a blind accept or a blind reject fromone or more of the candidate femtocells; and/or identifying one of thecandidate femtocells associated with a blind accept as the designatedfemtocell.

Some embodiments include a femtocell gateway that may include a macronetwork interface subsystem configured to communicate with a core nodeof a macro network and configured to receive communications from themacro network. The femtocell gateway may include a femtocell interfacesubsystem configured to communicate with multiple femtocells. Thefemtocell gateway may include a communications management subsystem,communicatively coupled with the macro network interface subsystem andthe femtocell interface subsystem, and may be configured to: receive,from the macro network, a handover request configured to direct a userequipment to hand off active communications with the macro network froma macrocell to a designated femtocell with a first femtocell identifier;determine whether any of the multiple femtocells registered the userequipment with the femtocell gateway prior to receiving the handoverrequest; and/or communicate the handover request to designatedfemtocell.

To determine whether any of the multiple femtocells registered the userequipment with the femtocell gateway prior to receiving the handoverrequest, the communications management subsystem may be configured to:determine a registering femtocell from the multiple femtocells that hasregistered the user equipment prior to receiving the handover request;and/or determine that the registering femtocell is the designatedfemtocell with the first femtocell identifier. The communicationsmanagement subsystem may be further configured to: receive anacknowledgement message from the registering femtocell.

To determine whether any of the multiple femtocells registered the userequipment with the femtocell gateway prior to receiving the handoverrequest, the communications management subsystem may be configured to:determine that none of the multiple femtocells registered the userequipment prior to receiving the handover request. The communicationsmanagement subsystem may be further configured to determine a set ofcandidate femtocells from the multiple femtocells. The candidatefemtocells may be identified by at least the first femtocell identifier.Each of the candidate femtocells may be directed to detect whether theuser equipment is in its proximity. An indication may be received from asuccessful femtocell of the candidate femtocells that the user equipmentis in its proximity. It may be determined that the successful femtocellis the designated femtocell. The communications management subsystem maybe further configured to: monitor an elapsed time subsequent todirecting the set of candidate femtocells to detect whether the userequipment is in its proximity; and/or determine whether the indicationfrom one of the candidate femtocells that the user equipment is in itsproximity is received while the elapsed time is within a predefined timelimit.

To determine whether any of the multiple femtocells registered the userequipment with the femtocell gateway prior to receiving the handoverrequest, the communications management subsystem may be furtherconfigured to determine whether an OOB proximity indication is receivedfrom any of the multiple femtocells prior to receiving the handoverrequest, wherein the OOB proximity indication comprises a macroidentifier of the user equipment. To determine whether any of themultiple femtocells registered the user equipment with the femtocellgateway prior to receiving the handover request, the communicationsmanagement subsystem may be further configured to: determine whether anOOB proximity detection is received from any of the multiple femtocellsprior to receiving the handover request, wherein the OOB proximityindication comprises an OOB identifier of the user equipment; and/ordetermine a macro identifier of the user equipment corresponding to theOOB identifier of the user equipment.

In some embodiments, the communications management subsystem may befurther configured to: determine whether the designated femtocell isuniquely addressable by the femtocell gateway according to the firstfemtocell identifier. Communicating the handover request to designatedfemtocell may utilize the first femtocell identifier.

In some embodiments, the communications management subsystem configuredto determine whether any of the multiple femtocells registered the userequipment prior to receiving the handover request may include aconfiguration to: determine whether two or more femtocells of themultiple femtocells are addressable by the femtocell gateway accordingto the first femtocell identifier; and/or determine whether thedesignated femtocell is one of the two or more femtocells addressableaccording to the first femtocell identifier utilizing a second femtocellidentifier.

In some embodiments, the communications management subsystem may befurther configured to: determine a set of candidate femtocells from themultiple femtocells; and direct, using an OOB hand-in cause value in thehandover request, each of the candidate femtocells to detect whether theuser equipment is in its proximity. The communications managementsubsystem may be further configured to: receive an OOB accept messagefrom one of the candidate femtocells, wherein the OOB accept messageindicates that the one of the candidate femtocells detects the userequipment in its proximity; and/or identify the one of the candidatecells as the designated femtocell. The communications managementsubsystem may be further configured to: receive at least an OOB rejectmessage from one or more of the candidate femtocells or an errorindication message from one or more of the candidate femtocells and noOOB accept messages; and transmit to each of the candidate femtocells ahandover request with a normal cause value. The communicationsmanagement subsystem may be further configured to: receive at least ablind accept or a blind reject from one or more of the candidatefemtocells; and/or identify one of the candidate femtocells associatedwith a blind accept as the designated femtocell.

Some embodiments include a processor for macrocell-to-femtocell hand-inin a femtocell gateway. The processor may include a communicationsmanagement controller configured to: receive, from the macro network, ahandover request configured to direct a user equipment to hand offactive communications with the macro network from a macrocell to adesignated femtocell with a first femtocell identifier; determinewhether any of a plurality of femtocells registered the user equipmentwith the femtocell gateway prior to receiving the handover request;and/or communicate the handover request to the designated femtocell.

Some embodiments include a computer program product formacrocell-to-femtocell hand-in residing on a processor-readable mediumdisposed at a femtocell gateway and including a processor-readableinstructions, which, when executed, cause a processor to perform stepsthat may include receiving, from a macro network, a handover requestconfigured to direct a user equipment to hand off active communicationswith the macro network from a macrocell to a designated femtocell with afirst femtocell identifier; determining whether any of a plurality offemtocells registered the user equipment with the femtocell gatewayprior to receiving the handover request; and/or communicating thehandover request to the designated femtocell.

Some embodiments include system for macrocell-to-femtocell hand-in thatmay include: means for receiving, from a macro network, a handoverrequest configured to direct a user equipment to hand off activecommunications with the macro network from a macrocell to a designatedfemtocell with a first femtocell identifier; means for determiningwhether any of a plurality of femtocells registered the user equipmentwith the femtocell gateway prior to receiving the handover request;and/or means for communicating the handover request to the designatedfemtocell.

The foregoing has outlined rather broadly examples according todisclosure in order that the detailed description that follows may bebetter understood. Additional features will be described hereinafter.The conception and specific examples disclosed may be readily utilizedas a basis for modifying or designing other structures for carrying outthe same purposes of the present disclosure. Such equivalentconstructions do not depart from the spirit and scope of the appendedclaims. Features which are believed to be characteristic of the conceptsdisclosed herein, both as to their organization and method of operation,together with associated advantages will be better understood from thefollowing description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description only and not as a definition of the limitsof the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of examplesprovided by the disclosure may be realized by reference to the remainingportions of the specification and the drawings wherein like referencenumerals are used throughout the several drawings to refer to similarcomponents. In some instances, a sub-label is associated with areference numeral to denote one of multiple similar components. Whenreference is made to a reference numeral without specification to anexisting sub-label, the reference numeral refers to all such similarcomponents.

FIG. 1 shows a block diagram of a wireless communications system inaccordance with various embodiments;

FIG. 2A shows a block diagram of a wireless communications system thatincludes a femtocell in accordance with various embodiments;

FIG. 2B shows a block diagram of a wireless communications system thatanother femtocell in accordance with various embodiments;

FIG. 3 shows a block diagram of an example of a processor module forimplementing functionality of a communications management subsystem inaccordance with various embodiments;

FIG. 4 shows a block diagram of an example of a mobile user equipment inaccordance with various embodiments;

FIG. 5 shows a simplified network diagram of a communications system forfacilitating active hand-in using a femtocell in accordance with variousembodiments;

FIG. 6A shows a block diagram of a wireless communications system thatincludes a femtocell gateway in accordance with various embodiments;

FIG. 6B shows a block diagram of another femtocell gateway in accordancewith various embodiments;

FIG. 7A shows a flow diagram of a method for handling user equipmentregistration with a femtocell in accordance with various embodiments;

FIG. 7B shows a flow diagram of a method for handling user equipmentregistration with a femtocell using a Bluetooth radio for out-of-bandproximity detection in accordance with various embodiments;

FIG. 8 shows a flow diagram of a method for handling active hand-inswith a femtocell in accordance with various embodiments;

FIG. 9 shows a call flow diagram illustrating an active hand-in inaccordance with various embodiments such as the methods of FIGS. 9 and10;

FIG. 10 shows a flow diagram of a method for handling de-registration ofuser equipment with a femtocell in accordance with various embodiments;

FIG. 11 shows a flow diagram of a method for implementing certain activehand-in functionality without OOB proximity detection in accordance withvarious embodiments;

FIG. 12 shows a flow diagram of a method for handling femtocell-assistedactive hand-in at a femtocell gateway in accordance with variousembodiments;

FIG. 13A shows a flow diagram of a method for handlingfemtocell-assisted active hand-in at a femtocell gateway in accordancewith various embodiments;

FIG. 13B shows a flow diagram of a method for handlingfemtocell-assisted active hand-in at a femtocell gateway with a tieredapproach in accordance with various embodiments;

FIGS. 14A and 14B show call flow diagrams illustrating an active hand-inin accordance with various embodiments such the methods of FIGS. 11, 12,and/or and 13;

FIG. 15A shows a call flow diagram of a method for handling the receiptof handover requests when a “tiered” approach is used and OOB detectionis successful in accordance with various embodiments; and

FIG. 15B shows a call flow diagram of a method for handling the receiptof handover requests when the “tiered” approach is used and OOBdetection is unsuccessful in accordance with various embodiments.

DETAILED DESCRIPTION

The following description generally relates to supportingmacrocell-to-femtocell hand-ins of active macro communications formobile devices. A femtocell may detect a mobile device in its proximity(e.g., using an out-of-band link established by an out-of-band radiointegrated with the femtocell, which may be part of a femto-proxysystem). Having detected the mobile device in its proximity, thefemtocell may communicate an OOB proximity detection or presenceindication to pre-register the mobile device with a femtocell gateway(or other type of interface gateway) disposed in a core network incommunication with the macro network. When the femtocell gatewayreceives a handover request from the macro network implicating thepre-registered mobile device, the femtocell gateway may be able toreliably determine the appropriate femtocell to use for the hand-inaccording to the OOB proximity detection. Some embodiments also providefor registering the mobile device after a handover request has occurred.In addition, some embodiments may provide “tiered” approaches forhandling the receipt of handover requests.

The following description provides examples, and is not limiting of thescope, applicability, or configuration set forth in the claims. Changesmay be made in the function and arrangement of elements discussedwithout departing from the spirit and scope of the disclosure. Variousexamples may omit, substitute, or add various procedures or componentsas appropriate. For instance, the methods described may be performed inan order different from that described, and various operations may beadded, omitted, or combined. Also, features described with respect tocertain examples may be combined in other examples.

Referring first to FIG. 1, a block diagram illustrates an example of awireless communications system 100. The system 100 includes macrocellbase stations 105, user equipments (UEs) 115, a base station controller120, femtocell 125, and a core network 130 (the controller 120 may beintegrated into the core network 130). The system 100 may supportoperation on multiple carriers (waveform signals of differentfrequencies). Multi-carrier transmitters can transmit modulated signalssimultaneously on the multiple carriers. Each modulated signal may be aCode Division Multiple Access (CDMA) signal, Time Division MultipleAccess (TDMA) signal, Frequency Division Multiple Access (FDMA) signal,Orthogonal FDMA (OFDMA) signal, Single-Carrier FDMA (SC-FDMA) signal,etc. Each modulated signal may be sent on a different carrier and maycarry control information (e.g., pilot signals), overhead information,data, etc. The system 100 may be a multi-carrier LTE network capable ofefficiently allocating network resources.

The UEs 115 may be any type of mobile station, mobile device, accessterminal, subscriber unit, or user equipment. The UEs 115 may includecellular phones and wireless communications devices, but may alsoinclude personal digital assistants (PDAs), smartphones, other handhelddevices, netbooks, notebook computers, etc. Thus, the term userequipment (UE) should be interpreted broadly hereinafter, including theclaims, to include any type of wireless or mobile communications device.

The macrocell base stations 105 may wirelessly communicate with the UEs115 via a base station antenna. The macrocell base stations 105 may beconfigured to communicate with the UEs 115 under the control of thecontroller 120 via multiple carriers. Each of the base station 105 sitescan provide communication coverage for a respective geographic area. Insome embodiments, macrocell base stations 105 may be referred to as aNode B. The coverage area for each macrocell base station 105 here isidentified as 110-a, 110-b, or 110-c. The coverage area for a basestation may be divided into sectors (not shown, but making up only aportion of the coverage area). The system 100 may include base stations105 of different types (e.g., macro, micro, and/or pico base stations).As used herein, the term “cell” may refer to 1) a sector, or 2) a site(e.g., a base station 105). Thus, the term “macrocell” may refer to 1) amacrocell sector, 2) a macrocell base station (e.g., macrocell basestation 105), and/or 3) a macrocell controller. Thus, the term“femtocell” may refer to 1) a femtocell sector, or 2) a femtocell basestation (e.g., femtocell access point).

For the discussion below, the UEs 115 operate on (are “camped on”) amacro or similar network facilitated by multiple macrocell base stations105. Each macrocell base station 105 may cover a relatively largegeographic area (e.g., hundreds of meters to several kilometers inradius) and may allow unrestricted access by terminals with servicesubscription. A portion of the UEs 115 may also be registered to operate(or otherwise allowed to operate) in femtocell coverage area 110-d(e.g., communicating with femtocell 125, which may be referred to as afemtocell access point (FAP) in some cases), within the coverage area ofa macrocell 110-a. As a UE 115 approaches a femtocell, there may be needfor novel mechanisms for the UE 115 to recognize the presence of thefemtocell 125 so that the UE 115 may migrate to the femtocell 125 fromthe macrocell base station 105.

Strategic deployment of femtocells may be used to mitigate mobile devicepower consumption, as mobile devices typically operate using an internalpower supply, such as a small battery, to facilitate highly mobileoperation. Femtocells may be used to offload traffic and reduce spectrumusage at a macrocell. Femtocells may also be utilized to provide servicewithin areas which might not otherwise experience adequate or even anyservice (e.g., due to capacity limitations, bandwidth limitations,signal fading, signal shadowing, etc.), thereby allowing mobile devicesto reduce searching times, to reduce transmit power, to reduce transmittimes, etc. A femtocell 125 may provide service within a relativelysmall service area (e.g., within a house or building). Accordingly, a UE115 is typically disposed near a femtocell 110-d when being served,often allowing the UE 115 to communicate with reduced transmissionpower.

By way of example, the femtocell may be implemented as a Home Node B(“HNB”) or Home eNode B (HeNB), and located in a user premises, such asa residence, an office building, etc. Femtocell 125 will be usedhereinafter generically to describe any femtocell access point, andshould not be interpreted as limiting. The femtocell 125 location may bechosen for maximum coverage (e.g., in a centralized location), to allowaccess to a global positioning satellite (GPS) signal (e.g., near awindow), or in other locations. A set of UEs 115 may be registered on(e.g., on a whitelist of) a single femtocell 125 that provides coverageover substantially an entire user premises. The “home” femtocell 125provides the UE 115 with access to communication services via aconnection to the macrocell communications network. As used herein, themacrocell communications network is assumed to be a wireless wide-areanetwork (WWAN). As such, terms like “macrocell network” and “WWANnetwork” are interchangeable. Similar techniques may be applied to othertypes of network environments, femtocell coverage topologies, etc.,without departing from the scope of the disclosure or claims.

Systems, methods, devices, and computer program products are describedto identify target femtocells to facilitate femto-assisted activehand-ins. In example configurations, the femtocell 125 may be integratedwith one or more OOB transceivers. The femtocell 125 may transmit orreceive OOB discovery signals (e.g., Bluetooth page or inquiry signals)to or from a UE 115 to facilitate the exchange of femtocell and deviceinformation. The femtocell 125 may, of course, also be configured toconnect with a UE 115 via in-band signals. The femtocell 125 may detectthe UE 115 in proximity to the femtocell 125 using an OOB communicationslink. The femtocell 125 may identify an identifier of the UE 115. Thefemtocell 125 may register the UE 115 for hand-in from the macrocellbase station 105 for example, to the femtocell 125. The registrationprocess may include communicating, from the femtocell 125 to a femtocellgateway (not shown), the UE identifier and indicating OOB proximitydetection of the UE 115 to the femtocell 125.

As used herein, the term “frequency range” may be used to refer to thefrequency spectrum allocated to a particular macrocell or femtocell, orfor OOB signaling. A macrocell frequency range may be a first frequencychannel within a set of frequencies allocated to WWAN communications,and a femtocell frequency range may be a second frequency channel withinthe set of frequencies allocated to WWAN communications. The macrocellfrequency range and the femtocell frequency range may the same, ordifferent (therefore, there may be an intra-frequency or inter-frequencysearch for a femtocell). Additional macrocell frequency ranges mayoccupy other frequency channels within the set of frequencies allocatedto WWAN communications.

As used herein, “out-of-band,” or “OOB,” includes any type ofcommunications that are out-of-band with respect to the macrocell orfemtocell communications network. For example, a femtocell 125 and/orthe UE 115 may be configured to operate using Bluetooth (e.g., class 1,class 1.5, and/or class 2), ZigBee (e.g., according to the IEEE802.15.4-2003 wireless standard), near field communication (NFC), WiFi,an ultra-wideband (UWB) link, and/or any other useful type ofcommunications out of the macrocell network band.

OOB integration with the femtocell 125 may provide a number of features.For example, the OOB signaling may allow for reduced interference, lowerpower femtocell registration, macrocell offloading, and so on. Further,the integration of OOB functionality with the femtocell 125 may allowthe UEs 115 associated with the femtocell 125 to also be part of an OOBpiconet. The piconet may facilitate enhanced HNB functionality, othercommunications services, power management functionality, and/or otherfeatures to the UEs 115. These and other features will be furtherappreciated from the description below.

FIG. 2A shows a block diagram of a wireless communications system 200-athat includes OOB capabilities. This system 200-a may be an example ofaspects of the system 100 depicted in FIG. 1. The femtocell 125-a mayinclude an OOB frequency module 240-a, an in-band frequency module230-a, and/or a communications management subsystem 250. The in-bandfrequency module 230-a may be a femto Node B and/or radio networkcontroller, as described with reference to FIG. 1. The femtocell 125-aalso may include antennas 205, a transceiver module 210, memory 215, anda processor module 225, which each may be in communication, directly orindirectly, with each other (e.g., over one or more buses). Thetransceiver module 210 may be configured to communicatebi-directionally, via the antennas 205, with the UEs 115. Thetransceiver module 210 (and/or other components of the femtocell 125-a)may also be configured to communicate bi-directionally with a macrocommunications network 100-a (e.g., a WWAN). For example, thetransceiver module 210 may be configured to communicate with the macrocommunications network 100-a via a backhaul network. The macrocommunications network 100-a may be the communications system 100 ofFIG. 1.

The memory 215 may include random access memory (RAM) and read-onlymemory (ROM). In some embodiments, the memory 215 includes (or is incommunication with) a data store 217 configured to store UE mappings219. As described more fully below, these UE mappings 219 may be used tofacilitate certain femtocell-assisted hand-in functionality. Typicallythe UE mappings 219 map a identifier of each UE 115 (e.g., theInternational Mobile Subscriber Identity (IMSI) associated with the UE's115 SIM card) with an OOB identifier corresponding to the UE's 115 OOBradio (e.g., the UE's 115 Bluetooth address). In certain embodiments,further mappings are maintained for each UE 115 by the UE mappings 219including, for example, a public long code mask.

The memory 215 may also store computer-readable, computer-executablesoftware code 220 containing instructions that are configured to, whenexecuted, cause the processor module 225 to perform various functionsdescribed herein (e.g., call processing, database management, messagerouting, etc.). Alternatively, the software 220 may not be directlyexecutable by the processor module 225 but be configured to cause thecomputer, e.g., when compiled and executed, to perform functionsdescribed herein.

The processor module 225 may include an intelligent hardware device,e.g., a central processing unit (CPU) such as those made by Intel®Corporation or AMD®, a microcontroller, an application specificintegrated circuit (ASIC), etc. The processor module 225 may include aspeech encoder (not shown) configured to receive audio via a microphone,convert the audio into packets (e.g., 30 ms in length) representative ofthe received audio, provide the audio packets to the transceiver module210, and provide indications of whether a user is speakingAlternatively, an encoder may only provide packets to the transceivermodule 210, with the provision or withholding/suppression of the packetitself providing the indication of whether a user is speaking

The transceiver module 210 may include a modem configured to modulatethe packets and provide the modulated packets to the antennas 205 fortransmission, and to demodulate packets received from the antennas 205.While some examples of the femtocell 125-a may include a single antenna205, the femtocell 125-a preferably includes multiple antennas 205 formultiple links. For example, one or more links may be used to supportmacro communications with the UEs 115. Also, one or more out-of-bandlinks may be supported by the same antenna 205 or different antennas205.

Notably, the femtocell 125-a may be configured to provide both in-bandfrequency module 230-a and OOB frequency module 240-a functionality. Forexample, when the UE 115 approaches the femtocell coverage area, theUE's 115 OOB radio may begin searching for the OOB frequency module240-a. In some cases, the OOB frequency module 240-a may page the UE'sOOB radio. Upon discovery, the UE 115 may have a high level ofconfidence that it is in proximity to the femtocell coverage area, and ascan for the in-band frequency module 230-a may commence. Similarly, theOOB frequency module 240-a may be utilized by the femtocell 125-a todetermine that a UE 115 is in proximity to the femtocell 125-a.

The scan for the in-band frequency module 230-a may be implemented indifferent ways. For example, due to the OOB frequency module 240-adiscovery by the UE's 115 OOB radio, both the UE 115 and the femtocell125-a may be aware of each other's proximity. The UE 115 may scan forthe in-band frequency module 230-a. Alternatively, the in-band frequencymodule 230-a may poll for the UE 115 (e.g., individually, or as part ofa round-robin polling of all registered UEs 115), and the UE 115 maylisten for the poll. When the scan for the in-band frequency module230-a is successful, the UE 115 may attach to the in-band frequencymodule 230-a.

When the UE 115 is in the femtocell coverage area and is linked to thein-band frequency module 230-a through a communication link, the UE 115may be in communication with the macro communications network 100-a viathe in-band frequency module 230-a. As described above, the UE 115 mayalso be a slave of a piconet for which the OOB frequency module 240-aacts as the master. For example, the piconet may operate using Bluetoothand may include Bluetooth communications links facilitated by aBluetooth radio (e.g., implemented as part of the transceiver module210) in the in-band frequency module 230-a.

Examples of the in-band frequency module 230-a have variousconfigurations of base station or wireless access point equipment. Asused herein, the in-band frequency module 230-a may be a device thatcommunicates with various terminals (e.g., client devices (UEs 115,etc.), proximity agent devices, etc.) and may also be referred to as,and include some or all the functionality of, a base station, a Node B,Home Node B, and/or other similar devices. Although referred to hereinas the in-band frequency module 230-a, the concepts herein areapplicable to access point configurations other than femtocellconfiguration (e.g., picocells, microcells, etc.). Examples of thein-band frequency module 230-a utilize communication frequencies andprotocols native to a corresponding cellular network (e.g., the macrocommunications network 100-a, or a portion thereof) to facilitatecommunication within a femtocell coverage area associated with thein-band frequency module 230-a (e.g., to provide improved coverage of anarea, to provide increased capacity, to provide increased bandwidth,etc.).

The in-band frequency module 230-a may be in communication with otherinterfaces not explicitly shown in FIG. 2A. For example, the in-bandfrequency module 230-a may be in communication with a native cellularinterface as part of the transceiver module 210 (e.g., a specializedtransceiver utilizing cellular network communication techniques that mayconsume relatively large amounts of power in operation) forcommunicating with various appropriately configured devices, such as theUE 115, through a native cellular wireless link (e.g., an “in-band”communication link) Such a communication interface may operate accordingto various communication standards, including but not limited towideband code division multiple access (W-CDMA), CDMA2000, global systemfor mobile telecommunication (GSM), worldwide interoperability formicrowave access (WiMax), and wireless LAN (WLAN). Also oralternatively, the in-band frequency module 230-a may be incommunication with one or more backend network interfaces as part of thetransceiver module 210 (e.g., a backhaul interface providingcommunication via the Internet, a packet switched network, a switchednetwork, a radio network, a control network, a wired link, and/or thelike) for communicating with various devices or other networks.

As described above, the in-band frequency module 230-a may further be incommunication with one or more OOB interfaces as part of the transceivermodule 210 and/or the OOB frequency module 240-a. For example, the OOBinterfaces may include transceivers that consume relatively low amountsof power in operation and/or may cause less interference in the in-bandspectrum with respect to the in-band transceivers. Such an OOB interfacemay be utilized according to embodiments to provide low power wirelesscommunications with respect to various appropriately configured devices,such as an OOB radio of the UE 115. The OOB interface may, for example,provide a Bluetooth link, an ultra-wideband (UWB) link, an IEEE 802.11(WLAN) link, etc.

The terms “high power” and “low power” as used herein are relative termsand do not imply a particular level of power consumption. Accordingly,OOB devices (e.g OOB frequency module 240-a) may simply consume lesspower than native cellular interface (e.g., for macro WWANcommunications) for a given time of operation. In some implementations,OOB interfaces also provide relatively lower bandwidth communications,relatively shorter range communication, and/or consume relatively lowerpower in comparison to the macro communications interfaces. There is nolimitation that the OOB devices and interfaces be low power, shortrange, and/or low bandwidth. Devices may use any suitable out-of-bandlink, whether wireless or otherwise, such as IEEE 802.11, Bluetooth,PEANUT, UWB, ZigBee, an IP tunnel, a wired link, etc. Moreover, devicesmay utilize virtual OOB links, such as through use of IP basedmechanisms over a wireless wide area network (WWAN) link (e.g., IPtunnel over a WWAN link) that acts as a virtual OOB link.

OOB frequency module 240-a may provide various types of OOBfunctionality and may be implemented in various ways. An OOB frequencymodule 240-a may have any of various configurations, such as astand-alone processor-based system, a processor-based system integratedwith a host device (e.g., access point, gateway, router, switch,repeater, hub, concentrator, etc.), etc. For example, the OOB frequencymodule 240-a may include various types of interfaces for facilitatingvarious types of communications. In some embodiments, the OOB frequencymodule 240-a may be referred to as a femto-proxy module.

Some OOB frequency module 240-a include one or more OOB interfaces aspart of the transceiver module 210 (e.g., a transceiver that may consumerelatively low amounts of power in operation and/or may cause lessinterference than in the in-band spectrum) for communicating with otherappropriately configured devices (e.g., a UE 115) for providinginterference mitigation and/or femtocell selection herein through awireless link. One example of a suitable communication interface is aBluetooth-compliant transceiver that uses a time-division duplex (TDD)scheme.

OOB frequency module 240-a may also include one or more backend networkinterfaces as part of the transceiver module 210 (e.g., packet switchednetwork interface, switched network interface, radio network interface,control network interface, a wired link, and/or the like) forcommunicating with various devices or networks. An OOB frequency module240-a that is integrated within a host device, such as with in-bandfrequency module 230-a, may utilize an internal bus or other suchcommunication interface in the alternative to a backend networkinterface to provide communications between the OOB frequency module240-a and other devices, if desired. Additionally or alternatively,other interfaces, such as OOB interfaces, native cellular interfaces,etc., may be utilized to provide communication between the OOB frequencymodule 240-a and the in-band frequency module 230-a and/or other devicesor networks.

Various communications functions (e.g., including those of the in-bandfrequency module 230-a and/or the OOB frequency module 240-a) may bemanaged using the communications management subsystem 250. For example,the communications management subsystem 250 may at least partiallyhandle communications with the macro (e.g., WWAN) network, one or moreOOB networks (e.g., piconets, UE 115 OOB radios, other femto-proxies,OOB beacons, etc.), one or more other femtocells (e.g., in-bandfrequency module 230-a), UEs 115, etc. For example, the communicationsmanagement subsystem 250 may be a component of the femtocell 125-a incommunication with some or all of the other components of the femtocell125-a via a bus.

Various other architectures are possible other than those illustrated byFIG. 2A. The in-band frequency module 230-a and/or the OOB frequencymodule 240-a may or may not be collocated, integrated into a singledevice, configured to share components, etc. For example, the femtocell125-a of FIG. 2A has an integrated in-band frequency module 230-a andOOB frequency module 240-a that at least partially share components,including the antennas 205, the transceiver module 210, the memory 215,and the processor module 225.

The components of the femtocell 125-a may, individually or collectively,be implemented, in whole or in part, with instructions embodied in amemory, formatted to be executed by one or more general orapplication-specific processors. They may also be implemented with oneor more application specific integrated circuits (ASICs) adapted toperform some or all of the applicable functions in hardware.Alternatively, the functions may be performed by one or more otherprocessing units (or cores), on one or more integrated circuits. Inother embodiments, other types of integrated circuits may be used (e.g.,Structured/Platform ASICs, Field Programmable Gate Arrays (FPGAs), andother Semi-Custom ICs), which may be programmed in any manner known inthe art.

FIG. 2B shows a block diagram of a wireless communications system 200-bthat includes an architecture of a femtocell 125-b that is differentfrom the architecture shown in FIG. 2A. Similar to the femtocell 125-aof FIG. 2A, the femtocell 125-b includes an OOB frequency module 240-band an in-band frequency module 230-b. Unlike the system 125-a of FIG.2A, however, each of the OOB frequency module 240-b and the in-bandfrequency module 230-b has its own antenna 205, transceiver module 210,memory 215, and processor module 225. Both transceiver modules 210 areconfigured to communicate bi-directionally, via their respectiveantennas 205, with UEs 115. The transceiver module 210-1 of the in-bandfrequency module 230-b is illustrated in bi-directional communicationwith the macro communications network 100-b (e.g., typically over abackhaul network).

For the sake of illustration, the femtocell 125-b is shown without aseparate communications management subsystem 250. In someconfigurations, a communications management subsystem 250 is provided inboth the OOB frequency module 240-b and the in-band frequency module230-b. In other configurations, the communications management subsystem250 is implemented as part of the OOB frequency module 240-b. In stillother configurations, functionality of the communications managementsubsystem 250 is implemented as a computer program product (e.g., storedas software 220 in memory 215) of one or both of the OOB frequencymodule 240-b and the in-band frequency module 230-b.

The components of the femtocell 125-b may, individually or collectively,be implemented, in whole or in part, with instructions embodied in amemory, formatted to be executed by one or more general orapplication-specific processors. They may also be implemented with oneor more application specific integrated circuits (ASICs) adapted toperform some or all of the applicable functions in hardware.Alternatively, the functions may be performed by one or more otherprocessing units (or cores), on one or more integrated circuits. Inother embodiments, other types of integrated circuits may be used (e.g.,Structured/Platform ASICs, Field Programmable Gate Arrays (FPGAs), andother Semi-Custom ICs), which may be programmed in any manner known inthe art.

In yet other configurations, some or all of the functionality of thecommunications management subsystem 250 of system 200-a may implementedas a component of the processor module 225. FIG. 3 shows a block diagram300 of a processor module 225-a for implementing functionality of thecommunications management subsystem 250. The processor module 225-a mayinclude a WWAN communications controller 310 and a user equipmentcontroller 320. The processor module 225-a may be in communication(e.g., as illustrated in FIGS. 2A and 2B) with the OOB frequency module240 and/or the in-band frequency module 230. The WWAN communicationscontroller 310 may be configured to receive a WWAN communication (e.g.,a page) for a designated UE 115. The user equipment controller 320 maydetermine how to handle the communication, including affecting operationof the OOB frequency module 240 and/or the in-band frequency module 230.

Both the in-band frequency module 230-a of FIG. 2A and the in-bandfrequency module 230-b of FIG. 2B are illustrated as providing acommunications link only to the macro communications network 100-a.However, the in-band frequency module 230 may provide communicationsfunctionality via many different types of networks and/or topologies.For example, the in-band frequency module 230 may provide a wirelessinterface for a cellular telephone network, a cellular data network, alocal area network (LAN), a metropolitan area network (MAN), a wide areanetwork (WAN), the public switched telephone network (PSTN), theInternet, etc.

As described above, the femtocell 125 may be configured to communicatewith client devices, including the UEs 115. FIG. 4 shows a block diagram400 of mobile user equipment (UE) 115-a for use with the femtocell 125of FIGS. 2A and/or 2B in the context of the communications systems andnetworks of FIGS. 1-3. The UE 115-a may have any of variousconfigurations, such as personal computers (e.g., laptop computers, netbook computers, tablet computers, etc.), cellular telephones, PDAs,digital video recorders (DVRs), internet appliances, gaming consoles,e-readers, etc. For the purpose of clarity, the UE 115-a is assumed tobe provided in a mobile configuration, having an internal power supply(not shown), such as a small battery, to facilitate mobile operation.

The UE 115-a may include antennas 445, an in-band transceiver module410, an OOB transceiver module 405, memory 415, and a processor module425, which each may be in communication, directly or indirectly, witheach other (e.g., via one or more buses). The transceiver modules 405,410 may be configured to communicate bi-directionally, via the antennas445 with femtocells and macrocells. For example, the in-band transceivermodule 410 may be configured to communicate bi-directionally withmacrocell base stations 105 of a macrocell of FIG. 1, and with thefemtocell 125 of FIG. 1, 2A, or 2B. The OOB transceiver module 405 maybe configured to communicate bi-directionally with the femtocell 125 ofFIG. 1, 2A, or 2B. Each transceiver module 405, 410 may include a modemconfigured to modulate the packets and provide the modulated packets tothe antennas 445 for transmission, and to demodulate packets receivedfrom the antennas 445. While the UE 115-a may include a single antenna,the UE 115-a will typically include multiple antennas 445 for multiplelinks.

As generally referenced above, the OOB transceiver module 405 may beconfigured to communicate with a femtocell over one or more OOBcommunication links as described in more detail below. The OOBtransceiver module 405 at the mobile device 115-a may include aBluetooth transceiver for example.

The memory 415 may include random access memory (RAM) and read-onlymemory (ROM). The memory 415 may store computer-readable,computer-executable software code 420 containing instructions that areconfigured to, when executed, cause the processor module 425 to performvarious functions described herein (e.g., call processing, databasemanagement, message routing, etc.). Alternatively, the software 420 maynot be directly executable by the processor module 425 but be configuredto cause the computer (e.g., when compiled and executed) to performfunctions described herein.

The processor module 425 may include an intelligent hardware device,e.g., a central processing unit (CPU) such as those made by Intel®Corporation or AMD®, a microcontroller, an application specificintegrated circuit (ASIC), etc. The processor module 325 may include aspeech encoder (not shown) configured to receive audio via a microphone,convert the audio into packets (e.g., 30 ms in length) representative ofthe received audio, provide the audio packets to the in-band transceivermodule 410, and provide indications of whether a user is speakingAlternatively, an encoder may only provide packets to the in-bandtransceiver module 410, with the provision or withholding/suppression ofthe packet itself providing the indication of whether a user is speaking

According to the architecture of FIG. 4, the UE 115-a further includes acommunications management module 440. The communications managementmodule 440 may manage communications with a macrocell, femtocell, otherUEs 115 (e.g., acting as a master of a secondary piconet), etc. By wayof example, the communications management module 440 may be a componentof the UE 115-a in communication with some or all of the othercomponents of the UE 115-a via a bus. Alternatively, functionality ofthe communications management module 440 may be implemented as acomponent of a transceiver module 405, 410, as a computer programproduct, and/or as one or more controller elements of the processormodule 425.

Some components of the UE 115-a may, individually or collectively, beimplemented, in whole or in part, with instructions embodied in amemory, formatted to be executed by one or more general orapplication-specific processors. They may also be implemented with oneor more application specific integrated circuits (ASICs) adapted toperform some or all of the applicable functions in hardware.Alternatively, the functions may be performed by one or more otherprocessing units (or cores), on one or more integrated circuits. Inother embodiments, other types of integrated circuits may be used (e.g.,Structured/Platform ASICs, Field Programmable Gate Arrays (FPGAs), andother Semi-Custom ICs), which may be programmed in any manner known inthe art.

In many cases, it is desirable to support active hand-in from amacrocell (e.g., macrocell base stations 105 of FIG. 1) to the femtocell125 and/or active hand-out from the femtocell 125 to the macrocell basestation 105 using handovers to provide seamless voice and data serviceto active users (active UEs 115). Active handouts can be relativelysimple to implement and are supported by most operators with legacymacro networks 100 and UEs 115. However, active hand-in may bechallenging and may not typically be supported by operators.

For example, as a UE 115 moves during the course of activecommunications with the macro network 100 (e.g., during a voice call, anactive data transfer, etc.), a determination may be made that a handoveris needed (e.g., the current macrocell base station 105 signal maybecome weak). The need for a handover may be determined according tomeasurement reports sent by the active UE 115. Notably, the phrase“measurement report” may be generally associated with 3GPP networks, butis intended herein to include any similar types of measurement reportingin any similar type of network (e.g., including “PSMMs,” or pilotstrength measurements, in 3GPP2 networks).

The measurement reports may include a measurement of the strength of thepilot observed by the UE 115 and the forward link cell identifier of thetarget cell. The cell identifier may be any identifier used by the macronetwork 100 to identify a particular cell. For example, the cellidentifier may be a “PSC” (primary scrambling code) in a 3GPP network, a“PN offset” in a 3GPP2 network, etc. On a typical macro network 100,enough cell identifiers (e.g., PSC) may be available to substantiallyensure that, given the geographical distribution of the macrocell basestations 105, each macrocell base station 105 can effectively beuniquely identified by its cell identifier (e.g., by a Radio Networkcontroller (RNC) 120 in the macro network 100, a Serving GPRS SupportNode (SGSN) in the core of the network, etc.).

While macrocell base stations 105 may effectively be uniquely identifiedby the macro network 100, there are typically not enough remaining cellidentifiers to uniquely identify all femtocells, such as femtocell 125,and in particular, the in-band frequency modules 230 added to thenetwork. For example, a typical macro network 100 may have 512 PSCvalues available for assignment to all the cells in its network. PNoffsets may be reused on different carriers, in different geographicregions, etc. to extend the number of cells that can effectively beidentified without confusion. However, only a small portion of the PSCvalues may be available for use by the femtocells 125, through theirin-band frequency modules 230 (i.e., other than the values reserved foruse by macrocell base stations 105), and the number and density offemtocells 125 may be relatively large in some areas. For example, onlya small number of PSC values must be reused among possibly hundreds offemtocells 125 per macro sector.

When a handover is required for an active UE 115 to a macrocell basestation 105 (as a handover from another macrocell base station 105 or asa hand-out from a femtocell 125), the cell identifier provided in themeasurement report may be sufficient to reliably determine theappropriate macrocell base station 105 for hand-off. The activecommunication may be handed off to the correct target cell withoutambiguity. However, when a handover may be required for an active UE 115to a femtocell 125 (as a hand-in from a macrocell base station 105), thesame cell identifier provided in the measurement report may be shared bymultiple femtocells 125 in the same macro sector. As such, the cellidentifier alone may be insufficient to reliably determine theappropriate femtocells 125 for hand-in in all cases. For example, the UE115 may be near its femtocell 125, and it may be desirable to hand-in tothat femtocell 125, but another femtocell 125 in the macro sector may beassociated with the same cell identifier.

In some newer networks, additional identifiers are available that maymitigate or solve this issue. For example, in UMTS networks, cells maybe upgraded to broadcast system information (SI), location information,and/or other information that may make identification of a particularfemtocell 125 based only on its cell identifier(s) more unique andreliable. Upgraded UEs 115 can exploit new cell identifier(s), forexample, by decoding the system information of neighboring cells andreporting the identifiers in measurement reports during activecommunications. The controllers (which may include macro radio networkcontrols (RNC) 120 and/or Serving GPRS Support Node (SGSN) 550, shownbelow in FIG. 5) can then include the SI (e.g. CELL_ID, C) in thehandover messages to uniquely identify the target femtocell 125 (e.g.,to the femtocell gateway). This technique may only be available forcommunications between upgraded networks and upgraded UEs 115. Foroperators who do not want to upgrade the air interface, this techniquemay not be available. Likewise for operators who do want to upgradetheir networks (e.g. RNC 120 and SGSN 650 shown below in FIG. 6A) toforward the SI to the femtocell gateway, this technique may not beavailable.

Operators of legacy networks (including those desiring to communicatewith legacy UEs 115) may address this difficulty with active hand-in indifferent ways. Some typical networks may not support active hand-in atall. In the event that the hand-in may be the only way to maintain theactive communications with the UE 115, the active communications maysimply be lost (e.g., a call may be dropped when signals from macrocellbase station 105 are lost, even when the UE 115 is otherwise in thefemtocell coverage area).

According to at least one technique for addressing the difficulty withactive hand-in in legacy networks, some operators may implement blindhandover. For example, when the measurement report includes a cellidentifier that is shared by multiple femtocells 125 in the same macrosector, the network may blindly select any of the femtocells 125 havingthat cell identifier for the hand-in. If blind selection results inhand-in to an appropriate femtocell 125, the hand-in may be successful.However, if blind selection results in hand-in to an inappropriatefemtocell 125 (e.g., one that is out of range of the UE 115, one forwhich the UE 115 is not authorized to attach, etc.), the activecommunications may be lost.

It will now be appreciated that operators of legacy systems may beunable to reliably support active hand-ins to femtocells 125 usingexisting techniques. Embodiments include novel techniques for supportingactive hand-ins for legacy networks and/or for legacy UEs 115. Turningto FIG. 5, a simplified network diagram is shown of a communicationssystem 500 for facilitating active hand-in.

The communications system 500 may include a macro network 100, a userlocal network 510, and a core network 530. The core network 530 mayinclude, among other things, a femtocell gateway 540 and/or a SGSN 550.The femtocell gateway 540 may be in communication with a number offemtocells 125 (only one femtocell 125 is shown for clarity), and theSGSN 550 is in communication with multiple macrocell base stations 105via one or more macro RNCs 120 (only one macrocell base station 105 isshow for clarity). The femtocell 125 is in communication through in-bandfrequency module 230 with the macro network 100 via core network 530elements, such that cellular communications may be facilitated throughthe femtocell 125 using functionality of the femtocell gateway 540and/or SGSN 550.

A UE 115 in active communications with the macrocell base station 105(over a macro communications link 560-b) may approach a coverage area ofthe femtocell 125. As described above, the macro network 100 (e.g., themacro RNC 120) may determine that a handover is needed based on ameasurement report from the UE 115. The measurement report may identifythe target femtocell 125 by its cell identifier (e.g., its PSC). Ahandover request may then be sent by the SGSN 550 to the targetfemtocell gateway 540 for identifying an appropriate femtocell 125 forthe hand-in.

As discussed, particularly where multiple femtocells 125 share a cellidentifier, it may be difficult or impossible for the femtocell gateway540 to reliably determine the appropriate target femtocell 125 forhand-in using the cell identifier alone. Some embodiments may exploitfeatures of femtocell 125. As shown, the user local network 510 includesthe in-band frequency module 230 functionality integrated with OOBfunctionality of an OOB frequency module 240 as part of a femtocell 125.This OOB functionality may be facilitated over an OOB communicationslink 570 that can be established between the UE 115 and the OOBfrequency module 240. This in-band functionality may be facilitated overan in-band communications link 550-a that can be established between theUE 115 and the in-band frequency module 230. The in-band communicationslink 550-a may be established, for example, when a hand-in occurs frommacrocell 105 to femtocell 125.

While many different types of out-of-band communications may be used tofacilitate functionality described here (e.g., as discussed above), thediscussion below focuses on Bluetooth as facilitating the OOBcommunications of these embodiments. Other embodiments may utilize othertypes of out-of-band communications. Bluetooth may provide certainfeatures. One feature is that Bluetooth radios may be integrated intomany UEs 115, so that the Bluetooth functionality can be exploited formany users without modifying their existing UEs 115. Another feature isthat the tolerable path loss between two “Class 1.5” Bluetooth devicesmay be comparable or even higher than between a femtocell 125 and a UE115. In any given environment, this higher tolerable path loss maytranslate to higher effective range (e.g., facilitating femtocell 125discovery, handover, and/or interference mitigation, as describedherein).

Yet another feature of Bluetooth is that the Bluetooth address (BD_ADDR)can provide a unique, 48-bit address used to identify each Bluetoothenabled device. The Bluetooth address may be used when a devicecommunicates with another device, and is divided into a 24-bit LAP(Lower Address Part), a 16-bit NAP (Non-significant Address Part), andan 8-bit UAP (Upper Address Part). The LAP may be assigned by amanufacturer and may be unique for each Bluetooth device, while UAP andNAP may be part of an Organizationally Unique Identifier (OUI). Usingthe Bluetooth address, each Bluetooth adapter in any device may beidentified according to a globally unique value.

As described more fully below, embodiments may operate in the context ofa system, like the communications system 500 of FIG. 5, to supportactive hand-ins with minimal or no change to legacy macro networks 100and/or to legacy UEs 115. One set of such embodiments uses modificationsto UEs 115 and the femtocell gateway 540 to facilitate active hand-in.In particular, an OOB identifier of the femtocell 125 may be detected bythe UE 115 and communicated as part of the measurement report tofacilitate identification of the target femtocell 125 by the femtocellgateway 540.

Each of the UE 115 and the femtocell 125 (through OOB frequency module240, for example) may have a unique Bluetooth device address (BD_ADDR)that may be used for paging the other device (e.g., UE 115 pages thefemtocell 125 or the femtocell 125 pages the UE 115). It is understoodthat the BD_ADDR of the other device may be known by the paging device.Notably, the same or similar techniques may be used for other types ofout-of-band addressing. For example, the devices may know each other'sWiFi MAC address, etc. The UE 115 may then assist the macro network 100in effecting the active hand-in.

In some embodiments, after an OOB communications link 570 is establishedwith the OOB frequency module 240 of the femtocell 125, the UE 115 cancommunicate a cell identifier (e.g., PSC) and the OOB identifier (e.g.,Bluetooth device address) of the target femtocell 125 to the SGSN 550 aspart of its measurement report. The femtocell gateway 540 may maintain amapping between the cell identifier and the OOB identifier, which canthen be used to uniquely identify the target femtocell 125 for activehand-in.

One technique may involve upgrades at the UE 115 “air-interface” (i.e.,new messages or modifications of existing messages are involved). Also,proper communication of new UE 115 messaging may involve changes to themacro RNCs 120, the SGSN 550, the femtocell gateway 540, and thefemtocell 125 (and in particular, the in-band frequency module 230 ofthe femtocell 125). These changes to the legacy macro network 100 maylargely be software upgrades (rather than hardware upgrades), butoperators may still be reluctant to implement the changes.

Another set of embodiments supports active hand-ins for both macronetworks 100 and UEs 115, which may be legacy macro networks 100 and/orlegacy UEs 115 in some cases. In particular, changes to the femtocell125 and/or the femtocell gateway 540 may allow for femtocell 125assisted active hand-in. Embodiments of femtocell 125 assisted hand-inmay be implemented without changes to the air-interface, the macro RNC120, or the SGSN 550. Femtocell 125 assisted hand-in may exploitregistration by the femtocell 125 of UEs 115 at the femtocell gateway540 (e.g., using OOB proximity detection to effectively pre-register theUE 115 with the femtocell gateway 540). When a handover directive isreceived at the femtocell gateway 540 implicating a UE 115, registrationof the UE 115 can be used by the femtocell gateway 540 to help determinethe appropriate target femtocell 125 for hand-in.

As described above with reference to FIG. 2A, embodiments of thefemtocell 125 may maintain UE mappings 219. Typically, the UE mappings219 map a macro identifier of each UE 115 (e.g., the InternationalMobile Subscriber Identity (IMSI), Mobile Equipment Identifier (MEID),Electronic Serial Number (ESN), etc.) with an OOB identifiercorresponding to the UE's 115 OOB radio (e.g., Bluetooth device address,WiFi MAC address, etc.). When the femtocell 125 is a restricted accessfemtocell, the UE mappings 219 may be maintained only for authorizedusers. For example, an access control list may be maintained at thefemtocell 125 that includes or is associated with the UE mappings 219.

Notably, there may various ways to establish the UE mappings 219.According to one exemplary technique, the UE 115 calls a particularnumber, which may automatically trigger an OOB pairing (e.g., aBluetooth pairing) between the UE 115 and the femtocell 125. Thus, themapping between the UE macro identifier and OOB identifier may beestablished. According to another exemplary technique, a user manuallyenters the UE's 115 macro identifier (e.g., IMSI) and OOB identifier(e.g., BD_ADDR) into a user interface at the femtocell 125. According toyet another exemplary technique, a user enters the mapping informationvia a portal (e.g., a web page), and the femtocell 125 downloads theinformation (e.g., or the femtocell 125 includes a web server and theportal directly addresses femtocell 125). In yet another exemplarytechnique, the OOB identifier of the UE can be entered into the portalby using a sniffer, an OOB-enabled device that wirelessly obtains theOOB identifier and reports it to the portal.

Active hand-in functionality described herein may involve use of afemtocell 125 having an in-band frequency module 230 integrated with anOOB frequency module 240. As illustrated in FIG. 5, and as described ina number of exemplary configurations above, the OOB frequency module 240includes an OOB device (e.g., an OOB radio) that is communicativelycoupled with the in-band frequency module 230. For example, the in-bandfrequency module 230 and the OOB frequency module 240 may be physicallyintegrated into a single housing or assembly (e.g., and in communicationover a bus or some other internal connection), or the OOB frequencymodule 240 may be separately housed and may be in communication with thein-band frequency module 230 using a wired or wireless connection.Typically, the OOB frequency module 240 is located close enough to thein-band frequency module 230 so that proximity detection by the OOBfrequency module 240 indicates proximity also to the in-band frequencymodule 230.

In some other configurations, the OOB frequency module 240 is logically,rather than physically, integrated with the in-band frequency module 230(e.g., the components can otherwise be logically associated with eachother by the network). For example, even having the OOB frequency module240 physically separated from the in-band frequency module 230, thecomponents may be part of a common subnet so that proximity detection bythe OOB frequency module 240 can be associated with proximity to thein-band frequency module.

The configuration described in FIG. 5 is intended only to beillustrative, and not limiting. Other configurations are possible forproviding the same or similar types of integrative functionality betweenOOB frequency module 240 and in-frequency module 230. For example, manyconfigurations may allow OOB proximity detection to be used tofacilitate reliable active hand-in to a particular femtocell 125,according to various embodiments.

To facilitate femtocell 125 assisted hand-in, femtocells 125, like theone described in FIG. 2A for example, may interact with embodiments offemtocell gateway 540, such as those described in FIG. 6A and FIG. 6B.FIG. 6A shows a block diagram of a wireless communications system 600-athat includes a femtocell gateway 540-a. The femtocell gateway 540-a mayinclude a communications management subsystem 610, a femto interfacesubsystem 630, and/or a macro interface subsystem 640. The femtocellgateway 540-a also may include memory 615 and a processor module 625.All the components of the femtocell gateway 540-a may be incommunication with each other directly or indirectly (e.g., over one ormore buses).

For the sake of context and clarity, the femto interface subsystem 630is shown in communication with femtocell 125 (which includes in-bandfrequency module 230 and OOB frequency module 240), and the macrointerface subsystem 640 is shown in communication with macrocell basestation 105 (via an SGSN 550 and/or one or more macro RNCs 120). Variouscommunications functions, including those involved in facilitatingfemtocell 125 assisted hand-in are implemented and/or managed using thecommunications management subsystem 610. For example, the communicationsmanagement subsystem 610 may at least partially handle communicationswith macro network elements using functionality of the macro interfacesubsystem 640 and may at least partially handle communications withfemtocell 125 using functionality of the femto interface subsystem 630.For example, the communications management subsystem 610 may be acomponent of the femtocell gateway 540-a in communication with some orall of the other components of the femtocell gateway 540 via a bus.

The memory 615 may include random access memory (RAM) and read-onlymemory (ROM). In some embodiments, the memory 615 is configured tomaintain registration-related information. As described more fullybelow, the registration-related information may include identifiermappings for femtocells 125, UEs 115, etc., as well as registrationmessages, flags, etc.

The memory 615 may also store computer-readable, computer-executablesoftware code 620 containing instructions that are configured to, whenexecuted, cause the processor module 625 to perform various functionsdescribed herein (e.g., call processing, database management, messagerouting, etc.). Alternatively, the software 620 may not be directlyexecutable by the processor module 625 but be configured to cause thecomputer, e.g., when compiled and executed, to perform functionsdescribed herein.

The processor module 625 may include an intelligent hardware device,e.g., a central processing unit (CPU) such as those made by Intel®Corporation or AMD®, a microcontroller, an application specificintegrated circuit (ASIC), etc. Embodiments of the processor module 625may be configured to facilitate functionality, such as timerfunctionality. Further, embodiments of the processor module 625 includeor facilitate some or all of the functionality of the communicationsmanagement subsystem 610, the femto interface subsystem 630, or themacro interface subsystem 640.

For example, FIG. 6B shows a block diagram of a wireless communicationssystem 600-b that includes a femtocell gateway 540-b that is analternate configuration of the femtocell gateway 540-a of FIG. 6A. Aswith the femtocell gateway 540-a of FIG. 6A, the femtocell gateway 540-bof FIG. 6B may include a femto interface subsystem 630, a macrointerface subsystem 640, memory 615, and/or a processor module 625,which may all be in communication with each other directly or indirectly(e.g., over one or more buses). Unlike the femtocell gateway 540-a ofFIG. 6A, the femtocell gateway 540-b of FIG. 6B may includecommunications management controller 610. Embodiments of thecommunications management controller 610 may be implemented as part ofthe processor module 625 to provide substantially the same functionalityas that of the communications management subsystem 610 shown in FIG. 6A.

As discussed above, embodiments of femtocell gateway 540, such as thosedescribed in FIGS. 6A and 6B, can interact with femtocells 125, like theone described in FIG. 2A, to facilitate femtocell 125 assisted hand-in.For example, when a UE 115 approaches a femtocell 125, the femtocell 125may detect the UE 115 in its proximity using an OOB link (e.g.,Bluetooth paging procedure) or vice versa. In addition to or as part ofthe OOB detection procedure, the femtocell 125 may determine whether theUE 115 is an authorized user. For example, the femtocell 125 may checkan access control list to determine whether the UE 115 is authorized toaccess macro communications services via the femtocell 125.

Having discovered each other (and the femtocell 125 having validated theUE 115 as an authorized user), the femtocell 125 may register the UE 115with the femtocell gateway 540. For example, the femtocell 125 maymaintain a UE mapping 219 between the UE's 115 OOB identifier (e.g., theBluetooth device address,) detected during the detection procedure and amacro identifier of the UE 115, like the UE's 115 IMSI. The femtocell125 may register the UE 115 with the femtocell gateway 540 according tothe UE's 115 identifier(s).

In some embodiments, the OOB radio range (e.g., the edge of Bluetoothcoverage) may be greater than the femtocell 125 coverage range (forexample, the range of the in-band frequency module 230), such that thedetection and registration of the UE 115 may be performed before the UE115 detects the femtocell 125. Thus, in many cases, a, OOB proximitydetection or indication may be communicated by the femtocell 125 to thefemtocell gateway 540 for the UE 115 before any handover has beentriggered by a measurement report of the UE 115 (i.e., the UE 115 mayeffectively be “pre-registered” upon receipt of any handover requestimplicating the UE 115).

Notably, various types of registration or pre-registration may beavailable in the macro network 100 and/or femtocell 125 context. As usedherein, “registration” and “pre-registration” can intend to refer to theexisting UE registration in macro networks (and the communication ofthis message between the femtocell 125 and femtocell gateway 540 may betriggered by the OOB proximity detection). In another embodiment, theregistration refers to a message carrying an OOB proximity detectionspecifically to register a UE 115 with an femtocell gateway 540. When ahandover is triggered and a relocation request is received at thefemtocell gateway 540 (e.g., from the SGSN 650), the femtocell gateway540 may be able to correlate the UE registration with the handoverrequest (e.g., according to the UE's 115 macro identifier). With thisinformation, the femtocell gateway 540 can uniquely identify theappropriate target femtocell 125 and reliably proceed with the hand-in.If the existing UE 115 registration message in macro network is used forindicating the OOB proximity to femtocell gateway 540, the femtocellgateway 540 may create an entry for the UE 115 and the registeringfemtocell 125 in a registration database as it would for regular UEregistrations not indicating OOB proximity. Later on, when a handover istriggered and a relocation request is received at the femtocell gateway540 (e.g., from the SGSN 650), the femtocell gateway 540 may use theentry in the database to correlate the UE 115 with registration in thedatabase with the handover request (e.g., according to the UE's 115macro identifier). With this information, the femtocell gateway 540 canuniquely identify the appropriate target femtocell 125 and reliablyproceed with the hand-in.

In some cases, the femtocell gateway 540 communicates the handoverrequest to the femtocell 125 with a flag indicating that femtocellgateway 540 thinks that the UE 115 is in proximity of the femtocell 125based on the femtocell's 125 prior registration with the UE's 115 macroidentifier (e.g., IMSI). Having received the flag, the femtocell 125 maytry to detect the UE 115 again (e.g., over an OOB channel using the OOBfrequency module 240). If the UE 115 is no longer in the femtocell's 125proximity, the femtocell 125 can reject the handover request from thefemtocell gateway 540. Further certain types of de-registrationtechniques may be used, as described below.

According to one de-registration technique, a UE 115 is explicitlyderegistered by communicating an OOB absence indication to the femtocellgateway 540. For example, the OOB frequency module 240 and/or thein-band frequency module 230 may detect link loss with the UE 115 andsend a de-registration request to the femtocell gateway 540 in the formof an OOB absence indication. According to another de-registrationtechnique, a UE 115 may be de-registered if a certain amount of timeelapses after registration without receiving a corresponding handoverrequest. According to yet another de-registration technique, a UE 115may be explicitly or implicitly de-registered upon acknowledgement ofhandover to the target femtocell 125.

In some embodiments, registration is only performed for active UEs 115.In one illustrative scenario, as described above, registration is basedon detection over an OOB communication link and subsequent communicationto the femtocell gateway 540 of an OOB proximity detection orindication. In this scenario, the femtocell 125 may not know whether theUE 115 is in WWAN idle state or active state (e.g., in a voice call).For idle handover, the femtocell's 125 pre-registration with thefemtocell gateway 540 with the UE's 115 macro identifier (e.g., IMSI) isignored. For example, implicit de-registration may occur if a handoverrequest message does not arrive at femtocell gateway 540 prior to atimeout.

In another illustrative scenario, a handover request message arrives atthe femtocell gateway 540 (e.g., as a relocation request message fromthe core network 130 of FIG. 1) implicating a UE 115. Even if the UE 115has been pre-registered, the femtocell gateway 540 may send a handoverrequest to the femtocell 125 with a flag indicating that the femtocellgateway 540 believes the UE 115 is in proximity of that specificfemtocell 125 based on the pre-registration. In some embodiments, thefemtocell 125 again tries to detect the UE 115 over the OOBcommunication link. If it fails, the femtocell 125 may reject thehandover request; if it succeeds, the femtocell 125 may accept thehandover request.

If the registration request is received at the femtocell gateway 540after a corresponding handover request implicating the UE 115 isreceived at the femtocell gateway 540, the femtocell gateway 540 mayhandle the hand-in in various ways, as described more fully below (e.g.,with reference to the call flow diagram of FIGS. 13-14). For example,even when the registration request is received after a correspondinghandover request, techniques described herein may be used to helpfacilitate active hand-in. Alternatively, there may be no hand-in, ortechniques described above may be used, like blind hand-in, etc.

It may be appreciated that the femtocell 125 assisted hand-in techniquesdescribed herein provide certain features. One feature may be that thetechniques may be used to reliably determine an appropriate targetfemtocell 125 for active hand-in. Another feature is thatpre-registration through communication of OOB proximity detection orindication may reduce or eliminate latencies relating to the blindhand-off technique. Yet another feature is that core network signaling(e.g., from measurement request and response) may be reduced. Andanother feature is that no changes may be needed in the UE 115, the airinterface, or the legacy infrastructure. The techniques may beimplemented with changes only to the femtocell 125 and/or the femtocellgateway 540.

Embodiments of femtocell 125 assisted hand-in techniques are describedbelow with reference to methods of FIGS. 7-14. Turning first to FIG. 7A,a flow diagram is shown of a method 700-a for macrocell-to-femtocellhand-in in accordance with various embodiments. The method 700-a may,for example, be performed by the femtocell 125 of FIG. 1, 2A, 2B, 5, 6A,or 6B. The method 700-a may begin at block 705 by detecting a UE 115 inproximity to a femtocell 125 using an OOB communications link. Thefemtocell 125 may be communicatively coupled with a macro network 100via a macrocell base station 105. For example, the UE 115 may be campedon the macrocell base station 125 and may or may not be in activecellular communications. The femtocell 125 may include includes an OOBfrequency module 240 and an in-band frequency module 230. The in-bandfrequency module 230 may include an HNB. The femtocell 125, through thein-band frequency module 230, may be communicatively coupled with themacro network 100 via a femtocell gateway 540. In some embodiments, thefemtocell gateway 540 may be a HNB gateway.

At block 710, an identifier of UE 115 on the macro network 100 may beidentified or determined by the femtocell 125 using the OOBcommunications link. For example, as part of detecting the UE 115 atblock 705, an OOB identifier corresponding to the UE 115 (e.g., theBD_ADDR) may be detected using the OOB frequency module 240 over an OOBcommunications link. In some embodiments, a macro identifier (e.g.,IMSI) associated with the UE 115 may be identified. As discussed above,the femtocell 125 may maintain UE mappings 219 between a correspondingOOB identifier and identifier for a particular UE 115.

In some embodiments, a determination is made as to whether the UE 115 isauthorized to access the macro network 100 via the femtocell 125. Forexample, the femtocell 125 may maintain an access control list (e.g., a“white list”) with UEs 115 authorized to attach to the femtocell 125(e.g., authorized to access macro communications services via thefemtocell 125). If it is determined that the UE 115 is not authorized toaccess the macro network 100 via the femtocell 125, the method 700-a mayabort. For example, the method 700-a may ignore the UE 115. In someembodiments, the femtocell gateway 540 may determine whether the UE 115is authorized to access the macro network 100 via the femtocell 125. Ifit is determined that the UE 115 is authorized to access the macronetwork 100 via the femtocell 125, the femtocell 125 may proceed withregistering the UE 115 as described below.

At block 715, the UE 115 is registered for hand-in from the macrocellbase station 105 to the femtocell 125. This may be done bycommunicating, from the femtocell 125 to the femtocell gateway 540, theuser equipment identifier. In addition, the registering of the UE 115may indicate OOB proximity detection of the UE 115 with respect to thefemtocell 125. For example, the femtocell 125 may communicate at leastthe UE's 115 macro identifier to the femtocell gateway 540 as part of aregistration message. As discussed above, the OOB range may be greaterthan (e.g., or at least substantially the same as) the femtocell range,such that the blocks of the method 700-a (e.g., from the proximitydetection at block 705 to communication of the registration method atblock 715) may, in some cases, occur before the UE 115 enters thefemtocell range. In this way, the registration may occur before the UE's115 measurement report may indicate the femtocell 125 and before anyhandover to the femtocell 125 is determined by the macro network 100.

Registering the UE 115 for hand-in the macrocell 105 to the femtocell125 may include transmitting a registration message from the femtocell125 to the femtocell gateway 540. Registering the UE 115 for hand-infrom the macrocell 105 to the femtocell 125 may include transmitting anOOB indication message from the femtocell 125 to the femtocell gateway540. Some embodiments may utilize a UE mapping between a macroidentifier of the UE 115 with the OOB identifier to determine the userequipment identifier.

As described above with reference to FIG. 5, various configurations mayuse different types of OOB proximity detection to facilitateregistration (e.g., pre- and/or post-registration using OOB proximitydetection). For example, portions of the method 700-a may be different,depending on whether the OOB proximity detection was being performedusing a configuration like the one shown in FIG. 5 (e.g., using aBluetooth radio as an OOB frequency module 240 physically integratedwith the femtocell 125). For the sake of added clarity, an examplescenario is described in FIG. 7B.

Turning first to FIG. 7B, a flow diagram is shown of a method 700-b formacrocell-to-femtocell hand-in utilizing UE 115 registration at afemtocell gateway 540 using a femtocell 125 in accordance with variousembodiments. The method 700-b may, for example, be performed by thefemtocell 125 of FIG. 1, 2A, 2B, 5, 6A, or 6B. Method 700-b may beperformed in the context of a Bluetooth radio being used as an OOBfrequency module 240 physically integrated with a femtocell 125, forexample. For the sake of added clarity, reference numerals from FIG. 7Aare used with the addition of a lower-case “a” to indicate a possibleillustrative implementation of the corresponding block from FIG. 7A inthe context of FIG. 7B. Accordingly, the method 700-b begins with block705-a in which a Bluetooth radio, configured as an OOB frequency module240 integrated with a femtocell 125 is used to detect a UE 115 inproximity to the femtocell 125.

Block 705-a includes blocks 720 and 725. At block 725, a Bluetooth radio(i.e., OOB frequency module 240) periodically pages the UE 115 to seewhether the UE 115 is in its proximity. As used herein, “periodically”is intended broadly to convey types of signaling that arenon-continuous. For example, periodically may include signaling (e.g.,paging) at predefined intervals, according to particular thresholds,etc. At block 725, the Bluetooth radio of the femtocell detects aresponse from the UE 115 over a Bluetooth link. More generally, thefemtocell may page the UE 115 over an OOB communications link and thendetect a response to the paging from the UE 115 over the OOBcommunications link. The response may include an OOB identifier of theUE 115. In some embodiments, the response may include a macro identifierof the UE 115.

Having received the response from the UE 115, the femtocell 125 may beaware that the UE 115 is in proximity, and the femtocell 125 may knowthe Bluetooth device address (e.g., BD_ADDR) of the UE 115. As describedabove, the Bluetooth device address may effectively provide a uniqueout-of-band identifier for the UE 115. In some configurations, thefemtocell 125 makes further determinations. For example, as discussedabove, the femtocell 125 may determine whether the UE 115 is authorizedto access the macro network 100 via the femtocell 125, through thein-band frequency module 230, for example.

At block 710-a, a macro identifier identifying the UE 115 on the macronetwork 100 (e.g., the IMSI) may be determined. For example, UE mappings219 between a corresponding OOB identifier and macro identifier for aparticular UE 115 may be maintained by the femtocell 125, such that thefemtocell 125 may determine the macro identifier of the UE 115 from itscorresponding Bluetooth device address. Alternatively, the mappings maybe maintained at the femtocell gateway 540.

At block 715-a, the UE 115 may be registered for hand-in from themacrocell base station 105 to the target femtocell 125. In particular,the femtocell 125 may communicate an OOB proximity detection or OOBpresence indication to the femtocell gateway 540 with an identifier ofthe UE 115 to register the UE 115 with the femtocell gateway 540. Insome configurations, in which the UE mappings are maintained at thefemtocell 125, the OOB proximity detection or indiction may becommunicated to the femtocell gateway 540 with the UE's 115 macroidentifier (e.g., and OOB identifier, in some configurations). In otherconfigurations, in which the UE mappings are maintained at the femtocellgateway 540, the OOB proximity detection or indication may becommunicated to the femtocell gateway 540 with the UE's 115 OOBidentifier, and the femtocell gateway 540 may then determine the mappingto the corresponding macro identifier.

Using Bluetooth for proximity may provide a number of features. Forexample, Bluetooth may allow for relatively low-power paging, range thatmay be similar to that of the femtocell coverage area, etc. Further,many UEs 115 may already be equipped with Bluetooth radios, such thatthe techniques may be implemented with little or no changes to the UEs115. However, certain limitations may manifest in some configurations.For example, the femtocell 125 may need to be integrated with theBluetooth radio, and certain types of provisioning may be difficult.Further, when using an open-femtocell (e.g., no access control list) orenterprise-type configuration, it may be difficult or inefficient topage the large number of Bluetooth addresses corresponding to all UEs115 that may be in proximity. Some embodiments may utilize other formsof OOB communication to address these issues, or utilize other methodsdiscussed herein.

FIG. 8 shows a flow diagram of a method 800 for handling active hand-inswith a femtocell in accordance with various embodiments. The method 800may, for example, be performed by the femtocell 125 of FIG. 1, 2A, 2B,5, 6A, or 6B. The method 800 is shown in the context of block 715 ofFIG. 7A or FIG. 7B for added clarity. For the sake of illustration, themethod 800 is described for a UE 115 that was registered by thefemtocell 125 with the femtocell gateway 540, for example, according tothe method 700-a of FIG. 7A.

Accordingly, the method 800 may begin at block 805 by receiving ahandover request for a pre-registered UE 115 (a UE 115 for which OOBproximity detection has previously been communicated to the femtocellgateway 540) at the femtocell 125 from the femtocell gateway 540. Inthese cases, the handover request may be received subsequent toregistered the UE 115 from hand-in from the macrocell to the femtocell.In some embodiments, the femtocell 125 maintains an awareness of itsregistration of the UE 115, such that it is aware of the proximity ofthe UE 115 when the handover request is received. In other embodiments,the handover request includes a flag or other indication to thefemtocell 125 that the implicated UE 115 is believed to be in thefemtocell's 125 proximity (e.g., that the UE 115 has been pre-registeredby the femtocell 125 by communicating an OOB proximity detection to thefemtocell gateway 540).

At block 810, an acknowledgement message may be communicated from thefemtocell 125 to the femtocell gateway 540 in response to receiving thehandover request. The messaging between the femtocell 125 and thefemtocell gateway 540 may be implemented across one or more networks.For example, the acknowledgement message may be communicated from thefemtocell 125 to a secure gateway at the edge of a core network over anInternet Protocol Security (IPSec) tunnel, from the secure gateway to anIP Multimedia Subsystem (IMS) network in the core network, and from theIMS network to the femtocell gateway 540 in the core network.

At block 815, the pre-registered UE 115 is directed to hand in activecommunications from its currently connected (source) macrocell 105 tothe target femtocell 125. Notably, the UE 115 may not typically receiveany handover direction from the femtocell 125. Rather, the femtocell 125may acknowledge the handover request to indicate that it is anappropriate handover target, and macro network 100 elements (e.g., thesource macrocell 105) ultimately may communicate the handover directiveto the UE 115.

Merely by way of example, a call flow diagram 900 illustrating an activehand-in according to the methods 700 and 800 of FIGS. 7 and 8 is shownin FIG. 9. The call flow diagram 900 shows communications between a UE115, a currently connected (source) macrocell 105, RNC 120, a sourceSGSN 650, a target femtocell gateway 540, and two potential targetfemtocells 125-a and 125-b. For the sake of avoiding excess detail, thesignaling between source macrocell 105 in communication with a macro RNC120, is not shown. It is assumed for the sake of the call flow diagram900 that the potential target femtocells 125 have a common cellidentifier (e.g., they have the same PSC). As such, it may be necessaryto reliably determine the appropriate one of the potential targetfemtocells 125 to ensure a successful active hand-in.

The call flow diagram 900 begins at block 904 with the UE 115 currentlyengaged in an active macro communications, like a voice call or a datacall, that may be facilitated by the source SGSN 650 via the sourcemacrocell 105 and/or RNC 120. At some time, the UE 115 moves intoproximity of the OOB frequency module 240 associated with a first of thepotential target femtocell 125-a (e.g., the OOB frequency module 240 andan in-band frequency module 230 may integrated into the femtocell125-a). At block 908, the OOB frequency module 240 may detect the UE 115in its proximity (e.g., as in block 705 of FIG. 7A). At block 912, thefirst potential target femtocell 125-a may send an OOB proximitydetection or indication (e.g., a registration request) to the targetfemtocell gateway 540 to pre-register the UE 115 (e.g., according toblock 715 of FIG. 7A). At block 914, the target femtocell gateway 540may respond with a registration acceptance acknowledging the receptionof the registration request from the target femtocell 125-a, and thenmay confirm that an entry for the UE 115 and registering femtocell 125-ahave been created in the registration database.

At some time thereafter, the UE 115 may move into the femtocell coveragearea of the femtocell 125, detect the femtocell 125, and send ameasurement report to the source macrocell 105 and/or RNC 120 at block916. The measurement report may include the pilot strength of thefemtocell 125 as observed by the UE 115 and the PSC of the femtocell125. The source macrocell 105 and/or RNC 120 may determine that ahandover is required according to the measurement report and maycommunicate a relocation required message to the source SGSN 650 atblock 920. At block 924, the relocation required message may becommunicated (e.g., as a relocation request message over the corenetwork) from the source SGSN 650 to the target femtocell gateway 540.

Having received a relocation request, the target femtocell gateway 240may now determine which potential target femtocell 125 is the correcttarget for the hand-in. For example, the handover request may includethe IMSI of the UE 115 and the PSC of the target femtocell 125. However,in this exemplary case, two potential target femtocells 125 may have thesame PSC, such that one cannot be uniquely identified by the PSC alone.Using traditional techniques, as described above, the handover requestmay be addressed, for example, by ignoring the hand-in, by blindlyselecting one of the potential target femtocells 125, etc. However,having received the OOB proximity indication or UE registration messageat block 912, the target femtocell gateway 540 may reliably select thefirst potential target femtocell 125-a as the correct target femtocell125 for the hand-in.

At block 928, the target femtocell gateway 540 may send the handoverrequest to the first target femtocell 125-a. The first target femtocell125-a may respond to the target femtocell gateway 540 with a handoverresponse carrying an “accept” message at block 932. The handover maythen be communicated to the UE 115 via the core network and/or the macronetwork 100. Notably, while referred to generically herein in someinstances as “handover requests” for the sake of simplicity, eachrelated message may, in fact, be of a different form and/or purpose. Forexample, as illustrated, a handover response may be communicated fromthe target femtocell gateway 540 to the source SGSN 650 as a relocationresponse message at block 936; a relocation command may be communicatedfrom the source SGSN 650 to the source macrocell 105 and/or RNC 120 atblock 940; and/or a relocation command may be communicated from thesource macrocell 105 and/or RNC 120 to the UE 115 as a physical channelconfiguration message at block 944.

At block 948, the UE 115 may communicate an acknowledgement message, thephysical channel reconfiguration message to the source macrocell 105and/or RNC 120. At block 952, the UE 115 may attempt to detect andsynchronize with the first potential femtocell 125-a; and, at block 956,the UE 115 may communicate a handover complete message to the firstpotential target femtocell 125-a; and the first potential targetfemtocell 125-a may communicate the handover complete message to thetarget femtocell gateway 540 at block 960. Although not shown in thefigure, the handover complete message may be relayed to the sourcemacrocell 105 and/or RNC 120 so that the radio link set-up for the UE115 can be deleted. Having completed the hand-in, the UE's 115 activemacro communications (e.g., the voice call) continue at block 964facilitated by the appropriately identified target femtocell 125 (i.e.,previously the first potential target femtocell 125-a) instead of by thesource macrocell 125 and/or RNC 120.

It is worth noting that the call flow diagram 900 is intended to showone example of a exemplary call flow and is simplified in many ways toadd clarity. For example, while a “handover request” is discussed in anumber of blocks, it will be appreciated that each element maycommunicate the message in similar or different forms with similar ordifferent information included. As such, the call flow diagram 900should not be construed as limiting the scope of the disclosure orclaims.

It is further worth noting that it may be necessary or desirable tode-register UEs 115 in certain cases. For example, suppose that a UE 115is registered by a first femtocell 125-a. Later, the UE 115 may moveinto proximity of a second femtocell 125-b that may have the same PSC ofthe first femtocell 125-a, but may be located well out of range of thefirst femtocell 125-a (e.g., miles away). The UE 115 may send ameasurement report with the shared PSC, triggering a handover request.At this block, the femtocell gateway 540 may have to use one or moretechniques to determine that handover to the second femtocell 125-b,rather than to the first femtocell 125-a, is desired. Otherwise,registration by the first femtocell 125-a may cause the femtocellgateway 540 to attempt a hand-in of the active communications of the UE115 from its current macrocell 105 to the first femtocell 125-a, eventhough the UE 115 is well out of range of the first femtocell 125, whichmay cause undesirable results (e.g., an active voice call may bedropped). Registration time stamps, de-registration, and/or othertechniques described herein may be used to address this issue, asdescribed more fully below.

FIG. 10 shows a flow diagram of a method 1000 for handlingde-registration of UEs in accordance with various embodiments. Themethod 1000 may, for example, be performed by the femtocell 125 of FIG.1, 2A, 2B, 5, 6A, or 6B. The method 1000 is shown in the context ofblock 715 of FIG. 7A for added clarity. For the sake of illustration,the method 1000 is described for a UE 115 that was registered by thefemtocell 125 with the femtocell gateway 540, for example, according tothe method 700-a of FIG. 7A.

The method 1000 may begin at block 1005 by determining whether an OOBcommunications link between the OOB frequency module 240 and theregistered UE 115 has been lost. As described above (e.g., withreference to block 705 of FIG. 7A), an OOB communications link may beestablished between the UE 115 and an OOB frequency module 240associated with the target femtocell 125. If the OOB communications linkis lost (e.g., at all, for a predetermined minimum duration, etc.), thismay indicate that the UE 115 is no longer in proximity to the femtocell125.

If it is determined at block 1005 that the OOB communications link hasbeen lost (e.g., since registration of the UE 115), the UE 115 may bede-registered at the femtocell gateway 540 by the femocell 125 at block1010. If it is determined at block 1005 that the OOB communications linkhas not been lost, a further determination may be made at block 1015 asto whether a handover request has been received for the registered UE115 at the femtocell 125. If a handover request has not been received,the method 1000 may iterate through blocks 1005 and 1015 until eitherthe OOB communications link is determined to be lost at block 1005 orthe handover request is received at block 1015. If a handover requesthas been received for the registered UE 115 at the femtocell 125, theregistered UE 115 may be directed to hand-in (e.g., according to block815 of FIG. 8).

Certain embodiments may handle de-registration in other ways. Forexample, in one configuration, the method 1000 may explicitlyde-register the UE 115 after completing the hand-in (e.g., successfullyand/or unsuccessfully). Notably, however, it may be useful to maintainthe registration (i.e., not de-register the UE 115) even after hand-into provide the network with knowledge about the proximity of the UE 115and/or other types of information that can be gained from theregistration.

According to another configuration, when the UE 115 is registered at thefemtocell gateway 540, the registration is associated with a timestamp.For example, the registering femtocell 125 may communicate an OOBproximity detection that includes the UE's 115 macro identifier (e.g.,or OOB identifier) and a timestamp. If another femtocell 125subsequently sends a registration request to the femtocell gateway 540for the same UE 115, the new registration request may include a latertimestamp. The femtocell gateway 540 may then consider any priorregistration request to be invalid, and facilitate handover to thelater-requesting femtocell 125. For example, the UE 115 may implicitlybe de-registered from prior-requesting femtocell 125 upon receiving asubsequent registration request at the femtocell gateway 540.

According to still another configuration, timer-based de-registration isimplemented. For example, upon registering the UE 115, the femtocell 125may begin a timer (e.g., or otherwise begin tracking elapsed time). Acertain timeframe (e.g., one minute) may be determined after whichde-registration is appropriate. For example, setting the timeframe toosmall may cause the femtocell 125 to have to re-register the UE 115inefficiently, while setting the timeframe too large may allow the UE115 to enter coverage areas of other femtocells 125 potentially sharingthe same PSC prior to the de-registration. Notably, timer-basedde-registration may be undesirable in certain configurations. Forexample, after registration, a handover request may not be received fora long time due to the UE 115 being idle or due to some othercircumstance. If the UE 115 were implicitly de-registered prior toreceiving the handover request, benefits of the registration may belost.

FIGS. 7-10 are discussed above primarily in context of pre-registration(i.e., communicating the OOB proximity detection for a UE 115 prior toreceiving a handover request for the UE 115). It may be appreciated thatsimilar techniques may be used in cases where the OOB proximitydetection is communicated subsequent to receiving a handover requestimplicating the UE 115. For example, as described above, the femtocellgateway 540 may be unable to determine the appropriate target femtocell125 for hand-in based only on the cell identifier provided in thehandover request from the SGSN 650, and may communicate a handoverrequest to all candidate target femtocells 125 (e.g., simultaneously).

FIG. 11 shows a flow diagram of a method 1100 for implementing certainactive hand-in functionality without pre-registration (i.e., withouthaving communicated the OOB proximity detection for a UE 115 prior toreceiving a handover request for the UE 115) in accordance with variousembodiments. The method 1100 may, for example, be performed by thefemtocell 125 of FIG. 1, 2A, 2B, 5, 6A, or 6B. The method 1100 may beginat block 1105 by receiving a handover request at a femtocell 125 via itsin-band frequency module 230 from a femtocell gateway 540 for adesignated UE 115. The femtocell gateway 540 may send the handoverrequest to a set of candidate femtocells that share the same PSCs. Notethat the handover request may be sent to each femtocell with a “dummyID”, instead of the target femtocell macro identifier. The “dummy ID”may indicate to the femtocell 125 that the handover request is for a PSCconfusion scenario where multiple candidate femtocells 125 have beenidentified, hence, an OOB capable femtocell 125 may use an OOB detectionof a designated UE 115 (a UE with mapping between a UE macro identifierand OOB identifier stored in the femtocell). Otherwise, the femtocell125 may use legacy techniques like blind support or no support torespond to the handover request.

At block 1110, the femtocell 125 may confirm that the UE 115 has anentry in the UE mappings 219 between the UE macro identifier and OOBidentifier. For example, if the UE 115 is in the femtocell's 125 UEmappings 219 (e.g., in the femtocell's 125 access control list), thefemtocell 125 may be able to use the UE's 115 IMSI, etc. to determinethe UE's 115 OOB identifier (e.g., BD_ADDR). Then the OOB frequencymodule 240 of the femtocell 125 may be used to detect the UE 115 over anOOB communications channel. Note that if a mapping for the UE was notfound in UE mapping 219, the femtocell 125 may be unable to use OOBdetection and hence, send a handover response based on other techniquessuch as blind support or no support as shown in block 1115.

Having used OOB communication to detect the UE 115 at block 1120, adetermination is made at block 1125 as to whether the UE 115 is detectedin proximity to the femtocell 125. If it is determined at block 1125that the UE 115 is not detected in proximity to the femtocell 125, thefemtocell 125 may communicate a detection failure response to thefemtocell gateway 540 at block 1130 through a handover response with a“reject” flag. If it is determined at block 1125 that the UE 115 isdetected in proximity to the femtocell 125, femtocell 125 maycommunicate a detection successful response to the femtocell gateway 540at block 1135.

Having successfully detected the UE 115 in its proximity, the femtocell125 may handle the hand-in in various ways. According to one technique,the femtocell 125 registers the UE 115 for hand-in to the femtocellgateway 540 (e.g., by communicating the cell identifier of the UE 115from the femtocell 125 to the femtocell gateway 540 in a registrationmessage such as with block 715 of FIG. 7A) followed by a handoverresponse with an “accept” flag 1145. According to another technique, thefemtocell 125 communicates successful proximity detection with ahandover response with an “accept” and “OOB indicator” flags 1140. Thereception of an OOB indicator in a handover response message at block1228 or a UE 115 registration preceding the handover response with an“accept” flag at block 908, alerts the femtocell gateway 540 to the factthat the handover response is based on OOB detection and the UE has beensuccessfully detected. The femtocell gateway may give precedence to suchresponses over handover responses based on other techniques like blindhand-off or no support since these techniques are less reliable. Havingcommunicated a successful detection to the femtocell gateway 540, theUE's 115 communications may be handed over to the femtocell 125 in areliable fashion.

FIGS. 7-11 focus primarily on handling of hand-in functionality from theperspective of a femtocell 125. As described above and as illustrated bythe call flow diagram 900 of FIG. 9, active hand-in functionality isfurther facilitated by actions of the femtocell gateway 540. Techniquesfor handling of hand-in functionality from the perspective of afemtocell gateway 540 are described in FIGS. 12-14.

Turning to FIG. 12, a flow diagram is shown of a method 1200 forhandling femtocell-assisted hand-in at a femtocell gateway in accordancewith various embodiments. The method 1200 may, for example, be performedby the femtocell gateway 540 of FIG. 5, 6A, or 6B. The method 1200 maybegin at block 1205 a handover request may be received, at a femtocellgateway 540 from a macro network 100. The handover request may beconfigured to direct a UE 115 to hand off active communications with themacro network 100 from a macrocell 105 to a designated femtocell 125with a first femtocell identifier.

At block 1210, it may be determined at the femtocell gateway 540 whetherany of multiple femtocells 125 registered the UE 115 with the femtocellgateway 540 prior to receiving the handover request. Block 1210 mayinclude determining whether an OOB proximity detection is received fromany of the multiple femtocells prior to receiving the handover request.The OOB proximity detection may include a macro identifier of the UE115, such as an IMSI. The OOB proximity detection may include an OOBidentifier of the UE 115. In some cases, the femtocell gateway 540 maydetermine whether the macro identifier of the UE 115 corresponds to theOOB identifier of the UE 115. In some embodiments, the femtocell gateway540 may determine whether two or more femtocells of the multiplefemtocells are addessable by the femtocell gateway 540 according to thefirst femtocell identifier. The femtocell gateway 540 may then determinewhether the designated femtocell is one of the two or more femtocellsaddressable according to the first femtocell identifier utilizing asecond femtocell identifier.

At block 1215, the femtocell gateway 540 may communicate the handoverrequest to the designated femtocell 125. Some embodiments of method 1200may further include determining whether the designated femtocell 125 isuniquely addressable by the femtocell gateway 540 according to the firstfemtocell identifier. Communicating the handover request from thefemtocell gateway 540 to designated femtocell may utilize the firstfemtocell identifier.

Turning to FIG. 13A, a flow diagram is shown of a method 1300-a forhandling femtocell-assisted active hand-in at a femtocell gateway inaccordance with various embodiments. The method 1300-a may, for example,be performed by the femtocell gateway 540 of FIG. 5, 6A, or 6B. Themethod 1300-a may begin at block 1205 by receiving a handover request atthe femtocell gateway 540 from a macro network 100 (e.g., from the SGSN650 over the core network). The handover request may be configured todirect a UE 115 to hand off active macro communications from a current(source) macrocell 105 to a designated femtocell 125. The designatedfemtocell 125 may be one of a number of femtocells 125 in communicationwith the femtocell gateway 540, and each femtocell 125 may beidentifiable by a first femtocell identifier (e.g., a PSC). Eachfemtocell 125 may also be identifiable by a second femtocell identifier,which may be a femtocell gateway-oriented identifier (e.g., anidentifier used by the femtocell gateway 540 to uniquely address all thefemtocells 125 in communication with the femtocell gateway 540). Notethat this femtocell gateway identifier can be similar to the uniqueidentifier broadcasted in the system information of the femtocells 125.In addition, the femtocell gateway 540 can send handover requests to thefemtocells 125 with an identifier termed the “dummy ID” which indicatesto the femtocells 125 that the handover request is for a PSC confusionscenario where multiple candidate femtocells 125 have been identified,hence, an OOB capable femtocell 125 with an OOB frequency module 240 mayuse the OOB detection for a designated UE 115. Otherwise, the femtocell125 may use legacy techniques like blind support or no support torespond to the handover request. Note that the “dummy ID” may have asimilar format as the femtocell gateway oriented identifier but it hasnot been assigned to any femtocell 125.

As described above, the first femtocell identifier may be substantiallynon-unique. For example, a number of femtocells 125 in the same macrosector may share the same first femtocell identifier (e.g., PSC). On thecontrary, the second femtocell identifier may be substantially orcompletely unique. For example, the second femtocell identifier may beat least unique enough so as to be used to reliably identify aparticular femtocell 125 from the perspective of the femtocell gateway540. It may be assumed that the designated femtocell 125 is identifiedin the handover request by its first femtocell identifier. For example,the first femtocell identifier may be how the femtocell 125 isidentified by the UE 115 as part of its measurement report, which isthen used to trigger the handover request.

At block 1210, a determination may be made as to whether any femtocells125 registered the macro identifier of the UE 115 (e.g., the IMSI) withthe femtocell gateway 540 prior to receiving the handover request at thefemtocell gateway 540. If it is determined at block 1210 that aparticular (“registering”) femtocell 125 registered the macro identifierof the UE 115 with the femtocell gateway 540 prior to receiving thehandover request at the femtocell gateway 540, the designated femtocell125 may be determined to be the “registering” femtocell 125 at block1305 (i.e., the “registering” femtocell 125 may be determined to be thetarget femtocell 125 for hand-in). Accordingly, at block 1215, thehandover request may be communicated from the femtocell gateway 540 tothe designated femtocell 125 (i.e., the “registering” femtocell 125)according to its second femtocell identifier. For example, the femtocellgateway 540 may maintain a mapping for all its connected femtocells 125between their respective first and second identifiers. The femtocellgateway 540 may uniquely address the handover request to the designatedfemtocell 125 by mapping the received first femtocell identifier (whichmay be substantially non-unique) to the maintained second femtocellidentifier (which may be substantially unique). After the handoverrequest is sent to the femtocell 125, at block 1310, an acknowledgementmessage (e.g. handover request message with an “accept” may be receivedby the femtocell gateway 540 from the designated femtocell 125.

If it is determined at block 1210 that no femtocells 125 registered themacro identifier of the UE 115 (using an OOB proximity detection or UEregistration message) with the femtocell gateway 540 prior to receivingthe handover request at the femtocell gateway 540, the femtocell gateway540 may use one or more techniques to handle the hand-in without beingable to exploit pre-registration. For example, at block 1315, a set ofcandidate target femtocells 125 may be determined from those femtocells125 registered at the femtocell gateway 540. For example, the femtocellgateway 540 may include in the set of candidates all femtocell 125 inthe relevant macro sector associated with the received first femtocellidentifier. As described above, the femtocell gateway 540 may sendhandover request for the designated UE 115 to any or a set of thefemtocells 125 in the candidate list.

In some embodiments, the handover request sent to the femtocells 125 ofthe candidate list are directed to detect the UE 115 at block 1320. Insome cases, the handover request may include a “dummy ID” so femtocells125 with OOB frequency modules 240 may be directed to detect the UE 115.For example, the femtocells 125 may engage in proximity detectionaccording to techniques described with reference to FIG. 11. It may bepossible that none of the candidate femtocells 125 will detect the UE115 in its proximity, or that multiple candidate femtocells 125 willdetect the UE 115 in their proximity. Various techniques may be used toabort the method 1300 where there is no successful detection, or toselect a “best” result when there are multiple successes. Notably,embodiments may use only OOB detection. Use of the OOB detection mayobviate the possibility that multiple successes would occur.Accordingly, and for the sake of clarity, it is assumed that one of thecandidate femtocells 125 is identifiable by the femtocell gateway 540 ashaving successfully detected the UE 115 in its proximity.

At block 1325, an indication is received at the femtocell gateway 540from one of the candidate femtocells 125 that the UE 115 is in itsproximity. The femtocell 125 that indicates that the UE 115 is in itsproximity may be referred to as a successful femtocell. This may be aregistration message accompanied by a handover response with an “accept”flag or a handover response with “accept” and “OOB indicator” flags,etc.

At block 1330, the femtocell gateway 540 may direct the designated UE115 to be handed over to the designated (registering) femtocell 125determined from blocks 1210, 1305, 1215, and/or 1310. Otherwise, ifthere was no pre-registration for the designated UE 115 in 1210, thefemtocell gateway 540 may direct the designated UE 125 to be handed overto the designated femtocell 125 determined from blocks 1210, 1315, 1320,and/or 1325.

In some embodiments, the femtocell gateway 540 may monitor an elapsedtime subsequent to directing the set of candidate femtocells 125 todetect whether UE 115 is in its proximity. The femtocell gateway 540 maydetermine whether the indication from one of the candidate femtocells125 that the UE 115 is in its proximity is received while the elapsedtime is within a predefined time limit. The femtocell gateway 540 maycommunicate the handover request to the designated femtocell 125 whenthe indication from the one of the candidate femtocells 125 that the UE115 is in its proximity is received within the predefined time limit.

Turning to FIG. 13B, a flow diagram is shown of a method 1300-b forhandling femtocell-assisted active hand-in at a femtocell gateway inaccordance with various embodiments. The method 1300-b may, for example,be performed by the femtocell gateway 540 of FIG. 5, 6A, or 6B. Method1300-b may utilize aspects of method 1300-a of FIG. 13A, such as blocks1205 that are not shown in this diagram. For the sake of added clarity,reference numerals from FIG. 13A may used with the addition of alower-case “a” to indicate a possible illustrative implementation orvariation of the corresponding block from FIG. 13A in the context ofFIG. 13B.

Method 1300-b may include at block 1210-a determining that none of theof multiple femtocells 125 registered the UE 115 prior to receiving thehandover request. At block 1315-a, a set of candidate femtocells 125from the multiple femtocells may be determined. The set of candidatefemtocells may be identified by at least the first femtocell identifierin some embodiments. At block 1335, each of the candidate femtocells 125may be directed with an OOB hand-in cause value in the handover requestto detect whether the UE 115 is in its proximity. The OOB hand-in causevalue may be unrecognizable by some femtocells 125, while somefemtocells 125 with OOB capabilities may recognize the OOB hand-in causevalue. A dummy identifier may also be transmitted in some cases. Block1335 may be referred to as a “first tier” handover request.

At block 1340, it may be determined whether an OOB accept message fromone of the candidate femtocells 125 is received. The OOB accept messagemay indicate that the one of the candidate femtocells 125 detects the UE115 in its proximity. If it is determined that an OOB accept message hasbeen received, the candidate femtocell 125 associated with the OOBaccept message may identified as the designated femtocell 125.

If an OOB accept message is not received, it may be that only OOB rejectmessage(s) from one or more of the candidate femtocells and/or errorindication message(s) from one or more of the candidate femtocells maybe received at block 1350. A “second tier” handover request may be madeas a result. At block 1355, a handover request with a normal cause valuemay be transmitting to each of the set of candidate femtocells 125. Thenormal cause value may be recognizable by the candidate femtocells 125in general. A dummy identifier may also be transmitted in some cases.The femtocell cells 125 may respond using legacy techniques such as ahandover response with blind accept or blind reject flag. At block 1360,at least a blind accept or a blind reject from one or more of thecandidate femtocells 125 may be received. At block 1365, the candidatefemtocell 125 associated with the blind accept may be identified as thedesignated femtocell.

At block 1330-a, the designated UE 115 may be directed to hand in fromits current connected macrocell 105 to the designated femtocell 125.

Exemplary call flow diagrams 1400-a and 1400-b, illustrating an activehand-in according to the methods 1100, 1200, and/or 1300-a of FIGS. 11,12, and/or 13A, respectively, are shown in FIG. 14A and FIG. 14B. Thecall flow diagrams 1400 are similar to the call flow diagram 900 of FIG.9, and similar messaging is described according to the same referencenumbers as those used in FIG. 9. It will be appreciated that themessaging, while similar, may not be identical according to thecircumstances of the different call flows. In particular, FIG. 9describes a pre-registration scenario, while FIGS. 14A and 14B describea post-registration scenario. In FIG.14A, a post-registration scenariois illustrated where the OOB proximity detection may be communicatedfrom the femtocell 125 to the femtocell gateway 540 by a combination ofUE registration message and a handover request with an “accept” flag. InFIG.14B, a post-registration scenario is illustrated where the OOBproximity detection may be communicated from the femtocell 125 to thefemtocell gateway 540 by a handover request with “accept” and OOBindicator flags.

As in FIG. 9, the call flow diagrams 1400 show communications between aUE 115, a currently connected (source) macrocell 105 and/or RNC120, asource SGSN 650, a target femtocell gateway 540, and two potentialtarget femtocell 125-a and 125-b. For the sake of avoiding excessdetail, the source macrocell base station may include a source macrocell105 in communication with a macro RNC 120, and signaling between thoseelements is not shown. It is assumed for the sake of the call flowdiagrams 1400 that the potential target femtocells 125 have a commoncell identifier (e.g., they have the same PSC). As such, it may benecessary to reliably determine the appropriate one of the potentialtarget femtocells 125 to ensure a successful active hand-in.

The call flow diagrams 1400 may begin at block 904 with the UE 115currently engaged in an active macro communications, like a voice callor a data call, facilitated by the source SGSN 650 via the sourcemacrocell 105 and/or the RNC 120. At some time, the UE 115 may move intothe femto coverage area of the femtocell 125, detect the femtocell 125,and send a measurement report to the source macrocell 105 and/or RNC 120at block 916. The measurement report may include the pilot strength ofthe femtocell 125 as observed by the UE 115 and the PSC of the femtocell125. The source source macrocell 105 and/or RNC 120 may determine that ahandover is required according to the measurement report andcommunicates a relocation required message to the source SGSN 650 atblock 920. At block 924, the relocation required message may becommunicated (e.g., as a relocation request message over the corenetwork) from the source SGSN 650 to the target femtocell gateway 540.

It is assumed in FIGS. 14A and 14B that, at the block when therelocation request 924 is received by the femtocell gateway 540, the UE115 has still not been registered by any femtocells 125 sharing theidentifier, such that multiple femtocells 125 may be candidate targetfemtocells 125 for the hand-in. In some cases, the femtocell gateway 540may send handover request with “dummy ID” to the candidate femtocells125 at block 1402. At block 1404, the OOB frequency module 240associated with a first of the potential target femtocell 125-a (e.g.,the OOB frequency module 240 and the in-band frequency module may beintegrated into the first potential target femtocell 125-a) detects theUE 115 in its proximity.

In FIG. 14A, when the UE 115 is detected by the first of the potentialtarget femtocell 125-a, the femtocell 125-a may send an OOB proximitydetection to the target femtocell gateway 540 by sending a registrationmessage for the designated UE 115 at block 1408 and a handover responsewith an “accept” flag at block 932. Having received the OOB proximitydetection and the handover request, the target femtocell gateway 540 candetermine the designated femtocell 125-a. . Note that the femtocell125-b may also receive the handover request at block 1402 and may replyback to the target femtocell gateway 540 with a handover response basedon blind off at block 1410. As described above, the target femtocellgateway 540 may distinguish the handover response based on OOB detectionfrom those based on the blind off, and hence can determine thedesignated femtocell 125-a.

In FIG. 14B, after OOB detection at block 1404, the femtocells 125 maysend handover response messages at block 1410. While multiple potentialtarget femtocells 125 may send handover response messages, only targetfemtocell 125-a (i.e., which detected the UE 115 in its proximity)communicates an OOB proximity detection to the femtocell gateway 540along with its handover response (e.g., by sending “accept” and OOBindicator flags at block 1406).

Irrespective of whether the OOB proximity detection or indicator in FIG.14A or FIG. 14B is used, the handover may then communicated to the UE115 via the core network and the macro network 100. Notably, whilereferred to generically herein in some instances as “handover requests”for the sake of simplicity, each related message may, in fact, be of adifferent form and/or purpose. For example, as illustrated, a handoverresponse may be communicated from the target femtocell gateway 540 tothe source SGSN 650 as a relocation response message at block 936; arelocation command may be communicated from the source SGSN 650 to thesource macrocell 105 and/or RNC 120 at block 940; and/or a relocationcommand may be communicated from the source macrocell 105 and/or RNC tothe UE 115 as a physical channel configuration message at block 944.

At block 948, the UE 115 may communicate an acknowledgement message, thephysical channel reconfiguration message to the source macrocell 105and/or RNC 120. At block 952, the UE may attempt to detect andsynchronize with the first potential femtocell 125-a. At block 956, theUE 115 may communicate a handover complete message to the firstpotential target femtocell 125-a; and the first potential targetfemtocell 125-a may communicate the handover complete message to thetarget femtocell gateway 540 at block 960. Although not shown in thefigure, the Handover complete message may be relayed to the sourcemacrocell 105 and/or RNC 120 so that the radio link set-up for the UE115 can be deleted. Having completed the hand-in, the UE's 115 activemacro communications (e.g., the voice call) continue at block 964facilitated by the appropriately identified target femtocell 125 (i.e.,previously the first potential target femtocell 125-a) instead of by thesource macrocell 105 and/or RNC 120.

Other embodiments for facilitating the active hand-in in apost-registration scenario may include tiered approaches. With thismethod, the femtocell gateway 540 may give priority to handoverresponses from OOB-capable femtocells 125 (e.g., those having an OOBfrequency module 240 that uses the OOB link for detection), overresponses from femtocells 125 that are not OOB-capable. Thisprioritization may be desirable because the responses based on OOBdetection may be more reliable than the default response configurationsin femtocells that typically involve a “blind” accept or reject of thehandover request.

In these embodiments, the femtocell gateway 540 may attempt to firstobtain handover responses based on OOB detection by sending “first tier”handover request targeted towards OOB-capable femtocells 125 only. If nohandover response with an “accept” flag is received by the femtocellgateway 540, the femtocell gateway 540 may send a “second tier” handoverrequest message to all candidate femtocells 125. The “tiered approach”can be implemented by defining a new “cause value” field in the handoverrequest, thereby obtaining “OOB capability awareness” from the corenetwork 130 of FIG. 1 about the femtocells 125 supported by thefemtocell gateway 540, etc. The “cause value” field may typically beused in handover request in deployed networks to communicate to thefemtocells 125 the reason for handover request.

In FIG. 15A and FIG. 15B, call flows for the embodiments in which the“cause value” is used in the “tiered approach” for post registrationdetection are discussed. FIG. 15A and/or FIG. 15B may illustrate anactive hand-in according to the method 1300-b of FIG. 13B. FIG. 15Aand/or FIG. 15B show aspects that may be implemented as aspects ofmethod 1300-b of FIG. 13B. FIG. 15A illustrates a scenario where OOBdetection is successful, and FIG. 15B illustrates a scenario where theOOB detection is unsuccessful. As in FIGS. 9, 14A, and/or 14B, the callflow diagrams 1500-a and 1500-b show communications between a UE 115, acurrently connected (source) macrocell 105 and/or RNC 105/120, a sourceSGSN 650, a target femtocell gateway 540, and two potential targetfemtocells 125. For the sake of avoiding excess detail, the sourcemacrocell base station may include the source macrocell 105 (which maybe source macro Node B) in communication with a macro RNC 120, andsignaling between those elements is not shown. It is assumed for thesake of the call flow diagrams 1500 that the potential target femtocells125 have a common cell identifier (e.g., they have the same PSC). Assuch, it may be necessary to reliably determine the appropriate one ofthe potential target femtocells 125 to ensure a successful activehand-in.

The call flow diagrams 1500 begin at block 904 with the UE 115 currentlyengaged in an active macro communications, like a voice call or a datacall, facilitated by the source SGSN 650 via the source macrocell 105and/or RNC 120. At some time, the UE 115 may move into the femtocoverage area of a femtocell 125, detect the femtocell 125, and send ameasurement report to the source macrocell 105 and/or RNC 120 at block916. The measurement report may include the pilot strength of thefemtocell 125 as observed by the UE 115 and the PSC of the femtocell125. The source macrocell 105 and/or RNC 120 may determine that ahandover is required according to the measurement report andcommunicates a relocation required message to the source SGSN 650 atblock 920. At block 924, the relocation required message is communicated(e.g., as a relocation request message over the core network) from thesource SGSN 650 to the target femtocell gateway 540.

It is assumed in FIG. 15A that at the block when the relocation request924 may be received by the femtocell gateways 540, the UE 115 has stillnot been registered by any femtocells 125 sharing the identifier, suchthat multiple femtocells 125 are candidate target femtocells 125 for thehand-in. As a result, the femtocell gateway 540 may send the “firsttier” handover request with “dummy ID” and an unrecognized “cause value”1502 (e.g. “OOB hand-in”) to the candidate femtocells 125. At block1504, femtocells 125 without the OOB capability (e.g., illustrated asfemtocell 125-b) respond back with an “error indication” in the handoverresponse. At block 1505, an OOB-capable femtocell 125 (e.g., illustratedas the first potential target femtocell. 125-a, which is assumed to beintegrated with an OOB frequency module 240) may detect the UE 115 inits proximity and send a handover response with an “accept” flag to thefemtocell gateway 540 at block 1506.

The handover may then be communicated to the UE 115 via the core networkand the macro network 100. Notably, while referred to generically hereinin some instances as “handover requests” for the sake of simplicity,each related message may, in fact, be of a different form and/orpurpose. For example, as illustrated, a handover response may becommunicated from the target femtocell gateway 540 to the source SGSN650 as a relocation response message at block 936; a relocation commandmay be communicated from the source SGSN 650 to the source macrocell 105and/or RNC 120 at block 940; and a relocation command may becommunicated from the source macrocell 105 and/or RNC 120 to the UE 115as a physical channel configuration message at block 944.

At block 948, the UE 115 may communicate an acknowledgement message, thephysical channel reconfiguration message to the source macrocell 105and/or RNC 120. At block 952, the UE 115 may attempt to detect andsynchronize with the first potential femtocell 125-a; at block 956, theUE 115 may communicate a handover complete message to the firstpotential target femtocell 125-a; and the first potential targetfemtocell 125-a may communicate the handover complete message to thetarget femtocell gateway 540 at block 960. Although not shown in thefigure, the Handover complete message may be relayed to the sourcemacrocell 105 and/or RNC 120 so that the radio link set-up for the UE115 can be deleted. Having completed the hand-in, the UE's 115 activemacro communications (e.g., the voice call) may continue at block 964facilitated by the appropriately identified target femtocell 125 (i.e.,previously the first potential target femtocell 125-a) instead of by thesource macrocell 105 and/or RNC 120.

It is assumed in FIG. 15B that, at the block when the relocation request924 is received by the femtocell gateway 540, the UE 115 may still notbeen registered by any femtocell 125 sharing the identifier, such thatmultiple femtocells 125 may be candidate femtocells 125 for the hand-in.As a result, the femtocell gateway 540 may send the “first tier”handover request with “dummy ID” and an unrecognized “cause value” 1502(e.g. “OOB hand-in”) to the candidate femtocells 125-b without the OOBcapability. At block 1504, femtocells 125 without the OOB capability(e.g., femtocells 125-b) may respond back to the femtocell gateway 540with an “error indication” in the handover response. At block 1508,OOB-capable potential target femtocells 125 (e.g., femtocells 125-a) mayrecognize the “cause value” and attempt to detect the UE 115 but thedetection was unsuccessful. Therefore, all such femtocells 125-a maysend handover responses with a “reject” flag 1510 to the femtocellgateway 540.

After the femtocell gateway 540 collects all the responses and nohandover response with an “accept” flag is received, the femtocellgateway 540 may then sends the “second tier” handover requests 1512 witha “dummy ID” and a “cause value” that can be recognized by all candidatefemtocells 125. The femtocells 125-a with OOB capability may not use theOOB detection, but instead all femtocells 125 respond to the handoverrequests 1512 using legacy techniques such as handover response withblind “accept” or “reject” flags. After the femtocell gateway 540receives the handover responses 1514, it may uses legacy active hand-insupport (which are typically less reliable than using the OOB detection)in implementing hand-in. This legacy support might require that thefemtocell gateway 540 to blindly select one femtocell 125 as thedesignated femtocell 125 or use other criterion (e.g. signal strength)to select the best “femtocell” 125 if such information is available atthe femtocell gateway 540.

If the femtocell gateway 540 had prior knowledge of which femtocells 125are OOB capable (OOB capability awareness), the “first tier” handoverrequest 1502 in FIGS. 15A and 15B can be sent only to femtocells 125-aand not to all candidate femtocells 125. This may reduce the signalinginvolved in the active hand-in process.

Techniques described herein may be used for various wirelesscommunication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, andother systems. The terms “system” and “network” are often usedinterchangeably. A CDMA system may implement a radio technology such asCDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0 and Aare commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) iscommonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD),etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. ATDMA system may implement a radio technology such as Global System forMobile Communications (GSM). An OFDMA system may implement a radiotechnology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA),IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc.UTRA and E-UTRA are part of Universal Mobile Telecommunication System(UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are newreleases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, andGSM are described in documents from an organization named “3rdGeneration Partnership Project” (3GPP). CDMA2000 and UMB are describedin documents from an organization named “3rd Generation PartnershipProject 2” (3GPP2). The techniques described herein may be used for thesystems and radio technologies mentioned above, as well as for othersystems and radio technologies.

The various operations of methods described above may be performed byany suitable means capable of performing the corresponding functions.The means may include various hardware and/or software component(s)and/or module(s), including, but not limited to a circuit, anapplication specific integrate circuit (ASIC), or processor.

The various illustrative logical blocks, modules, and circuits describedmay be implemented or performed with a general purpose processor, adigital signal processor (DSP), an ASIC, a field programmable gate arraysignal (FPGA), or other programmable logic device (PLD), discrete gate,or transistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. A generalpurpose processor may be a microprocessor, but in the alternative, theprocessor may be any commercially available processor, controller,microcontroller, or state machine. A processor may also be implementedas a combination of computing devices, e.g., a combination of a DSP anda microprocessor, a plurality of microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with thepresent disclosure, may be embodied directly in hardware, in a softwaremodule executed by a processor, or in a combination of the two. Asoftware module may reside in any form of tangible storage medium. Someexamples of storage media that may be used include random access memory(RAM), read only memory (ROM), flash memory, EPROM memory, EEPROMmemory, registers, a hard disk, a removable disk, a CD-ROM and so forth.A storage medium may be coupled to a processor such that the processorcan read information from, and write information to, the storage medium.In the alternative, the storage medium may be integral to the processor.A software module may be a single instruction, or many instructions, andmay be distributed over several different code segments, among differentprograms, and across multiple storage media.

The methods disclosed herein comprise one or more actions for achievingthe described method. The method and/or actions may be interchanged withone another without departing from the scope of the claims. In otherwords, unless a specific order of actions is specified, the order and/oruse of specific actions may be modified without departing from the scopeof the claims.

The functions described may be implemented in hardware, software,firmware, or any combination thereof If implemented in software, thefunctions may be stored as one or more instructions on a tangiblecomputer-readable medium. A storage medium may be any available tangiblemedium that can be accessed by a computer. By way of example, and notlimitation, such computer-readable media can comprise RAM, ROM, EEPROM,CD-ROM, or other optical disk storage, magnetic disk storage, or othermagnetic storage devices, or any other tangible medium that can be usedto carry or store desired program code in the form of instructions ordata structures and that can be accessed by a computer. Disk and disc,as used herein, include compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers.

Thus, a computer program product may perform operations presentedherein. For example, such a computer program product may be a computerreadable tangible medium having instructions tangibly stored (and/orencoded) thereon, the instructions being executable by one or moreprocessors to perform the operations described herein. The computerprogram product may include packaging material.

Software or instructions may also be transmitted over a transmissionmedium. For example, software may be transmitted from a website, server,or other remote source using a transmission medium such as a coaxialcable, fiber optic cable, twisted pair, digital subscriber line (DSL),or wireless technology such as infrared, radio, or microwave.

Further, modules and/or other appropriate means for performing themethods and techniques described herein can be downloaded and/orotherwise obtained by a user terminal and/or base station as applicable.For example, such a device can be coupled to a server to facilitate thetransfer of means for performing the methods described herein.Alternatively, various methods described herein can be provided viastorage means (e.g., RAM, ROM, a physical storage medium such as a CD orfloppy disk, etc.), such that a user terminal and/or base station canobtain the various methods upon coupling or providing the storage meansto the device. Moreover, any other suitable technique for providing themethods and techniques described herein to a device can be utilized.

Other examples and implementations are within the scope and spirit ofthe disclosure and appended claims. For example, due to the nature ofsoftware, functions described above can be implemented using softwareexecuted by a processor, hardware, firmware, hardwiring, or combinationsof any of these. Features implementing functions may also be physicallylocated at various positions, including being distributed such thatportions of functions are implemented at different physical locations.Also, as used herein, including in the claims, “or” as used in a list ofitems prefaced by “at least one of indicates a disjunctive list suchthat, for example, a list of “at least one of A, B, or C” means A or Bor C or AB or AC or BC or ABC (i.e., A and B and C). Further, the term“exemplary” does not mean that the described example is preferred orbetter than other examples.

Various changes, substitutions, and alterations to the techniquesdescribed herein can be made without departing from the technology ofthe teachings as defined by the appended claims. Moreover, the scope ofthe disclosure and claims is not limited to the particular aspects ofthe process, machine, manufacture, composition of matter, means,methods, and actions described above. Processes, machines, manufacture,compositions of matter, means, methods, or actions, presently existingor later to be developed, that perform substantially the same functionor achieve substantially the same result as the corresponding aspectsdescribed herein may be utilized. Accordingly, the appended claimsinclude within their scope such processes, machines, manufacture,compositions of matter, means, methods, or actions.

1. A method for macrocell-to-femtocell hand-in comprising: detecting auser equipment in proximity to a femtocell using an out-of-band (OOB)communications link; identifying a user equipment identifiercorresponding to the user equipment detected in proximity to thefemtocell using the OOB communications link; and registering the userequipment for hand-in from a macrocell to the femtocell bycommunicating, from the femtocell to a femtocell gateway, the userequipment identifier and indicating OOB proximity detection of the userequipment at the femtocell.
 2. The method of claim 1, whereinidentifying the user equipment identifier comprises receiving an OOBidentifier associated with the user equipment identifier over the OOBcommunications link.
 3. The method of claim 1, wherein identifying theuser equipment identifier comprises receiving a macro identifierassociated with the user equipment identifier over the OOBcommunications link.
 4. The method of claim 1, wherein registering theuser equipment for hand-in from the macrocell to the femtocell comprisestransmitting a registration message from the femtocell to the femtocellgateway.
 5. The method of claim 1, wherein registering the userequipment for hand-in from the macrocell to the femtocell comprisestransmitting an OOB indication message from the femtocell to thefemtocell gateway.
 6. The method of claim 2, further comprising:utilizing a user equipment mapping between a macro identifier of theuser equipment with the OOB identifier to determine the user equipmentidentifier.
 7. The method of claim 2, wherein detecting the userequipment in proximity to the femtocell comprises: paging the userequipment over the OOB communications link; and detecting a response tothe paging from the user equipment over the OOB communications link,wherein the response comprises the OOB identifier of the user equipment.8. The method of claim 1, further comprising: receiving a handoverrequest for the user equipment at the femtocell from the femtocellgateway, the handover request being configured to direct the userequipment to hand off active communications with the macro network fromthe macrocell to the femtocell.
 9. The method of claim 8, wherein thehandover request is received subsequent to registering the userequipment for hand-in from the macrocell to the femtocell.
 10. Themethod of claim 8, wherein: the handover request is received prior toregistering the user equipment for hand-in from the macrocell to thefemtocell; and detecting the user equipment comprises detecting the userequipment in response to receiving the handover request.
 11. The methodof claim 10, wherein detecting the user equipment in response toreceiving the handover request comprises: detecting the user equipmentover the OOB communications link utilizing an OOB identifier of the userequipment.
 12. The method of claim 1, further comprising: detecting aloss of the OOB communications link between the user equipment and thefemtocell; and de-registering the user equipment according to detectingthe loss of the OOB communications link.
 13. The method of claim 10,wherein registering the user equipment further comprises transmitting ahandover response accepting the handover request.
 14. The method ofclaim 1, wherein the femtocell is one of a plurality of femtocells on amacro network, each femtocell having a first femtocell identifieraccording to which the femtocell is non-uniquely addressable by themacro network and a second femtocell identifier according to which thefemtocell is uniquely addressable by the femtocell gateway.
 15. Themethod of claim 1, wherein the OOB communications link comprises aBluetooth link.
 16. The method of claim 14, wherein the first femtocellidentifier of each respective femtocell comprises a primary scramblingcode (PSC) of the respective femtocell.
 17. The method of claim 1,wherein the user equipment identifier comprises a macro identifierassociated with the user equipment.
 18. The method of claim 17, whereinthe macro identifier comprises a International Mobile SubscriberIdentity (IMSI) associated with the user equipment.
 19. A femtocellcomprising: an in-band frequency module, communicatively coupled with amacro network via a femtocell gateway and configured to provide cellularnetwork access to user equipments; an out-of-band (OOB) frequencymodule, communicatively coupled with the in-band frequency module andconfigured to communicate with the user equipments over an OOBcommunications link; and a communications management subsystem,communicatively coupled with the in-band frequency module and the OOBfrequency module, and configured to: detect a user equipment inproximity to the femtocell using an out-of-band (OOB) communicationslink; identify a user equipment identifier corresponding to the userequipment detected in proximity to the femtocell using the OOBcommunications link; and register the user equipment for hand-in from amacrocell to the femtocell by communicating, from the femtocell to afemtocell gateway, the user equipment identifier and indicating OOBproximity detection of the user equipment at the femtocell.
 20. Thefemtocell of claim 19, wherein the communications management subsystemconfigured to identify the user equipment identifier comprises aconfiguration to receive a macro identifier associated with the userequipment identifier over the OOB communications link.
 21. The femtocellof claim 19, wherein the communications management subsystem configuredto identify the user equipment identifier comprises a configuration toreceive an OOB identifier associated with the user equipment identifierover the OOB communications link.
 22. The femtocell of claim 19, whereinthe communications management subsystem configured to register the userequipment comprises a configuration to transmit a registration messagefrom the femtocell to the femtocell gateway.
 23. The femtocell of claim19, wherein the communications management subsystem configured toregister the user equipment comprises a configuration to transmit an OOBindication message from the femtocell to the femtocell gateway.
 24. Thefemtocell of claim 21, wherein the communications management subsystemis further configured to: utilize a user equipment mapping between amacro identifier of the user equipment with the OOB identifier todetermine the user equipment identifier.
 25. The femtocell of claim 20,wherein the communications management subsystem configured to detect theuser equipment in proximity to the femtocell is further configured to:page the user equipment over the OOB communications link; and detect aresponse to the paging from the user equipment over the OOBcommunications link, wherein the response comprises the macro identifierof the user equipment.
 26. The femtocell of claim 19, wherein thecommunications management subsystem is further configured to: receive ahandover request for the user equipment at the femtocell from thefemtocell gateway, the handover request being configured to direct theuser equipment to hand off active communications with the macro networkfrom the macrocell to the femtocell.
 27. The femtocell of claim 26,wherein the handover request is received subsequent to registering theuser equipment for hand-in from the macrocell to the femtocell.
 28. Thefemtocell of claim 26, wherein: the handover request is received priorto registering the user equipment for hand-in from the macrocell to thefemtocell; and the communications management subsystem configured todetect the user equipment comprises detecting the user equipment inresponse to receiving the handover request.
 29. The femtocell of claim28, wherein the communications management subsystem configured to detectthe user equipment in response to receiving the handover requestcomprises a configuration to: detect the user equipment over the OOBcommunications link utilizing an OOB identifier of the user equipment.30. The femtocell of claim 19, wherein the communications managementsubsystem is further configured to: detect a loss of the OOBcommunications link between the user equipment and the femtocell; andde-register the user equipment according to detecting the loss of theOOB communications link.
 31. The femtocell of claim 28, wherein thecommunications management subsystem is further configured to: transmit ahandover response accepting the handover request as part of registeringthe user equipment.
 32. The femtocell of claim 19, wherein the femtocellis one of a plurality of femtocells on a cellular network, eachfemtocell having a first femtocell identifier according to which thefemtocell is non-uniquely addressable by the macro network and a secondfemtocell identifier according to which the femtocell is uniquelyaddressable by the femto gateway.
 33. A processor formacrocell-to-femtocell hand-in, the processor comprising: acommunications management controller configured to: detect a userequipment in proximity to the femtocell using an out-of-band (OOB)communications link; identify a user equipment identifier correspondingto the user equipment detected in proximity to the femtocell using theOOB communications link; and register the user equipment for hand-infrom a macrocell to the femtocell by communicating, from the femtocellto a femtocell gateway, the user equipment identifier and indicating OOBproximity detection of the user equipment at the femtocell.
 34. Acomputer program product for macrocell-to-femtocell hand-in residing ona processor-readable medium and comprising processor-readableinstructions, which, when executed, cause a processor to perform stepscomprising: detecting a user equipment in proximity to a femtocell usingan out-of-band (OOB) communications link; identifying a user equipmentidentifier corresponding to the user equipment detected in proximity tothe femtocell using the OOB communications link; and registering theuser equipment for hand-in from a macrocell to the femtocell bycommunicating, from the femtocell to a femtocell gateway, the userequipment identifier and indicating OOB proximity detection of the userequipment at the femtocell.
 35. A system for macrocell-to-femtocellhand-in comprising: means for detecting a user equipment in proximity tothe femtocell using an out-of-band (OOB) communications link; means foridentifying a user equipment identifier corresponding to the userequipment detected in proximity to the femtocell using the OOBcommunications link; and means for registering the user equipment forhand-in from a macrocell to the femtocell by communicating, from thefemtocell to a femtocell gateway, the user equipment identifier andindicating OOB proximity detection of the user equipment at thefemtocell.
 36. A method for macrocell-to-femtocell hand-in, the methodcomprising: receiving, at a femtocell gateway from a macro network, ahandover request configured to direct a user equipment to hand offactive communications with the macro network from a macrocell to adesignated femtocell with a first femtocell identifier; determining, atthe femtocell gateway, whether any of a plurality of femtocellsregistered the user equipment with the femtocell gateway prior toreceiving the handover request; and communicating, from the femtocellgateway, the handover request to the designated femtocell.
 37. Themethod of claim 36, wherein determining, at the femtocell gateway,whether any of the plurality of femtocells registered the user equipmentwith the femtocell gateway prior to receiving the handover requestcomprises: determining a registering femtocell from the plurality offemtocells that has registered the user equipment prior to receiving thehandover request; and determining that the registering femtocell is thedesignated femtocell with the first femtocell identifier.
 38. The methodof claim 37, further comprising: receiving an acknowledgement messagefrom the registering femtocell.
 39. The method of claim 36, whereindetermining, at the femtocell gateway, whether any of the plurality offemtocells registered the user equipment with the femtocell gatewayprior to receiving the relocation request comprises: determining thatnone of the plurality of femtocells registered the user equipment priorto receiving the handover request.
 40. The method of claim 39, furthercomprising: determining a set of candidate femtocells from the pluralityof femtocells registered at the femto gateway, wherein the set ofcandidate femtocells is identified by at least the first femtocellidentifier; directing each of the set of candidate femtocells to detectwhether the user equipment is in its proximity; receiving an indicationfrom a successful femtocell of the candidate femtocells that the userequipment is in its proximity; and determining that the successfulfemtocell is the designated femtocell.
 41. The method of claim 40,further comprising: monitoring an elapsed time subsequent to directingthe set of candidate femtocells to detect whether the user equipment isin its proximity; and determining whether the indication from one of thecandidate femtocells that the user equipment is in its proximity isreceived while the elapsed time is within a predefined time limit. 42.The method of claim 36, wherein determining, at the femtocell gateway,whether any of the plurality of femtocells registered the user equipmentprior to receiving the handover request comprises: determining whetheran OOB proximity detection is received from any of the plurality offemtocells prior to receiving the handover request, wherein the OOBproximity indication comprises a macro identifier of the user equipment.43. The method of claim 36, wherein determining, at the femtocellgateway, whether any of the plurality of femtocells registered the userequipment prior to receiving the handover request comprises: determiningwhether an OOB proximity indication is received from any of theplurality of femtocells prior to receiving the handover request, whereinthe OOB proximity indication comprises an OOB identifier of the userequipment; and determining a macro identifier of the user equipmentcorresponding to the OOB identifier of the user equipment.
 44. Themethod of claim 36, further comprising: determining whether thedesignated femtocell is uniquely addressable by the femtocell gatewayaccording to the first femtocell identifier; and wherein communicating,from the femtocell gateway, the handover request to designated femtocellutilizes the first femtocell identifier.
 45. The method of claim 36,wherein determining, at the femtocell gateway, whether any of theplurality of femtocells registered the user equipment prior to receivingthe handover request comprises: determining whether two or morefemtocells of the plurality of femtocells are addressable by thefemtocell gateway according to the first femtocell identifier; anddetermining whether the designated femtocell is one of the two or morefemtocells addressable according to the first femtocell identifierutilizing a second femtocell identifier.
 46. The method of claim 39,further comprising: determining a set of candidate femtocells from theplurality of femtocells; and directing, using an OOB hand-in cause valuein the handover request, each of the set of candidate femtocells todetect whether the user equipment is in its proximity.
 47. The method ofclaim 46, further comprising: receiving an OOB accept message from oneof the candidate femtocells, wherein the OOB accept message indicatesthat the one of the candidate femtocells detects the user equipment inits proximity; and identifying one of the candidate cells associatedwith the OOB accept message as the designated femtocell.
 48. The methodof claim 46, further comprising: receiving at least an OOB rejectmessage from one or more of the candidate femtocells or an errorindication message from one or more of the candidate femtocells and noOOB accept messages; and transmitting to each of the candidatefemtocells a handover request with a normal cause value.
 49. The methodof claim 48, further comprising: receiving at least a blind accept or ablind reject from one or more of the candidate femtocells; andidentifying one of the candidate femtocells associated with a blindaccept as the designated femtocell.
 50. A femtocell gateway comprising:a macro network interface subsystem configured to communicate with acore node of a macro network and configured to receive communicationsfrom the macro network; a femtocell interface subsystem configured tocommunicate with a plurality of femtocells; and a communicationsmanagement subsystem, communicatively coupled with the macro networkinterface subsystem and the femtocell interface subsystem, andconfigured to: receive, from the macro network, a handover requestconfigured to direct a user equipment to hand off active communicationswith the macro network from a macrocell to a designated femtocell with afirst femtocell identifier; determine whether any of the plurality offemtocells registered the user equipment with the femtocell gatewayprior to receiving the handover request; and communicate the handoverrequest to designated femtocell.
 51. The femtocell gateway of claim 50,wherein to determine whether any of the plurality of femtocellsregistered the user equipment with the femtocell gateway prior toreceiving the handover request, the communications management subsystemis configured to: determine a registering femtocell from the pluralityof femtocells that has registered the user equipment prior to receivingthe handover request; and determine that the registering femtocell isthe designated femtocell with the first femtocell identifier.
 52. Thefemtocell gateway of claim 51, wherein the communications managementsubsystem is further configured to: receive an acknowledgement messagefrom the registering femtocell.
 53. The femtocell gateway of claim 50,wherein to determine whether any of the plurality of femtocellsregistered the user equipment with the femtocell gateway prior toreceiving the handover request, the communications management subsystemis configured to: determine that none of the plurality of femtocellsregistered the user equipment prior to receiving the handover request.54. The femtocell gateway of claim 53, wherein the communicationsmanagement subsystem is further configured to: determine a set ofcandidate femtocells from the plurality of femtocells, wherein thecandidate femtocells are identified by at least the first femtocellidentifier; direct each of the candidate femtocells to detect whetherthe user equipment is in its proximity; receive an indication from asuccessful femtocell of the candidate femtocells that the user equipmentis in its proximity; and determine that the successful femtocell is thedesignated femtocell.
 55. The femtocell gateway of claim 54, wherein thecommunications management subsystem is further configured to: monitor anelapsed time subsequent to directing the set of candidate femtocells todetect whether the user equipment is in its proximity; and determinewhether the indication from one of the candidate femtocells that theuser equipment is in its proximity is received while the elapsed time iswithin a predefined time limit.
 56. The femtocell gateway of claim 50,wherein to determine whether any of the plurality of femtocellsregistered the user equipment with the femtocell gateway prior toreceiving the handover request, the communications management subsystemis further configured to: determine whether an OOB proximity indicationis received from any of the plurality of femtocells prior to receivingthe handover request, wherein the OOB proximity indication comprises amacro identifier of the user equipment.
 57. The femtocell gateway ofclaim 50, wherein to determine whether any of the plurality offemtocells registered the user equipment with the femtocell gatewayprior to receiving the handover request, the communications managementsubsystem is further configured to: determine whether an OOB proximitydetection is received from any of the plurality of femtocells prior toreceiving the handover request, wherein the OOB proximity indicationcomprises an OOB identifier of the user equipment; and determine a macroidentifier of the user equipment corresponding to the OOB identifier ofthe user equipment.
 58. The femtocell gateway of claim 50, wherein thecommunications management subsystem is further configured to: determinewhether the designated femtocell is uniquely addressable by thefemtocell gateway according to the first femtocell identifier; andwherein communicating the handover request to designated femtocellutilizes the first femtocell identifier.
 59. The femtocell gateway ofclaim 50, wherein the communications management subsystem configured todetermine whether any of the plurality of femtocells registered the userequipment prior to receiving the handover request comprises aconfiguration to: determine whether two or more femtocells of theplurality of femtocells are addressable by the femtocell gatewayaccording to the first femtocell identifier; and determine whether thedesignated femtocell is one of the two or more femtocells addressableaccording to the first femtocell identifier utilizing a second femtocellidentifier.
 60. The femtocell gateway of claim 53, wherein thecommunications management subsystem is further configured to: determinea set of candidate femtocells from the plurality of femtocells; anddirect, using an OOB hand-in cause value in the handover request, eachof the candidate femtocells to detect whether the user equipment is inits proximity.
 61. The femtocell gateway of claim 60, wherein thecommunications management subsystem is further configured to: receive anOOB accept message from one of the candidate femtocells, wherein the OOBaccept message indicates that the one of the candidate femtocellsdetects the user equipment in its proximity; and identify the one of thecandidate cells as the designated femtocell.
 62. The femtocell gatewayof claim 60, wherein the communications management subsystem is furtherconfigured to: receive at least an OOB reject message from one or moreof the candidate femtocells or an error indication message from one ormore of the candidate femtocells and no OOB accept messages; andtransmit to each of the candidate femtocells a handover request with anormal cause value.
 63. The femtocell gateway of claim 62, wherein thecommunications management subsystem is further configured to: receive atleast a blind accept or a blind reject from one or more of the candidatefemtocells; and identify one of the candidate femtocells associated witha blind accept as the designated femtocell.
 64. A processor formacrocell-to-femtocell hand-in in a femtocell gateway, the processorcomprising: a communications management controller configured to:receive, from the macro network, a handover request configured to directa user equipment to hand off active communications with the macronetwork from a macrocell to a designated femtocell with a firstfemtocell identifier; determine whether any of a plurality of femtocellsregistered the user equipment with the femtocell gateway prior toreceiving the handover request; and communicate the handover request tothe designated femtocell.
 65. A computer program product formacrocell-to-femtocell hand-in residing on a processor-readable mediumdisposed at a femtocell gateway and comprising processor-readableinstructions, which, when executed, cause a processor to perform stepscomprising: receiving, from a macro network, a handover requestconfigured to direct a user equipment to hand off active communicationswith the macro network from a macrocell to a designated femtocell with afirst femtocell identifier; determining whether any of a plurality offemtocells registered the user equipment with the femtocell gatewayprior to receiving the handover request; and communicating the handoverrequest to the designated femtocell.
 66. A system formacrocell-to-femtocell hand-in comprising: means for receiving, from amacro network, a handover request configured to direct a user equipmentto hand off active communications with the macro network from amacrocell to a designated femtocell with a first femtocell identifier;means for determining whether any of a plurality of femtocellsregistered the user equipment with the femtocell gateway prior toreceiving the handover request; and means for communicating the handoverrequest to the designated femtocell.